I know this question has been answered before so if someone wants to post a link thats fine. I'm a good shooter and can hold a 1" group at 150yd with my Savage 110 .300 win mag but went shooting for the first time at 350yds and couldnt even hit a milk jug. Any suggestions?
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Range Report sub 1 MOA at 100, 4+ MOA at 350???
- Thread starter brant89
- Start date
Re: sub 1 MOA at 100, 4+ MOA at 350???
Yes, I live in southern Michigan and there aren't a lot of safe places to shoot over 150-200 yards. (I can get just over 600 in my field though.) I have shot my .17HMR at 250yd and held just over a 3" group. Everything felt solid and the accutrigger helps prevent anticipating the shot (and occasionally surprise you.) What could cause my group to open up from 1" at 150 to over 12" at 350?
Yes, I live in southern Michigan and there aren't a lot of safe places to shoot over 150-200 yards. (I can get just over 600 in my field though.) I have shot my .17HMR at 250yd and held just over a 3" group. Everything felt solid and the accutrigger helps prevent anticipating the shot (and occasionally surprise you.) What could cause my group to open up from 1" at 150 to over 12" at 350?
Re: sub 1 MOA at 100, 4+ MOA at 350???
That is the sad part about Michigan. We have no long-distance ranges around here
http://www.michigan.gov/documents/dnr/Long_Distance_Ranges_in_Michigan_344921_7.pdf
I found a full list of ranges there
That is the sad part about Michigan. We have no long-distance ranges around here
http://www.michigan.gov/documents/dnr/Long_Distance_Ranges_in_Michigan_344921_7.pdf
I found a full list of ranges there
Re: sub 1 MOA at 100, 4+ MOA at 350???
I've read about this topic at length, and also the reverse phenomenon, where you can't shoot a good group at 100, but can hold 1 moa or better at 600 yards.
The answer is there is no known scientific explanation for it. PhD's and scientists understand ballistics, gyroscopic stability, spin drift etc etc etc very well, and have complex models that *very* accurately predict spin-stabilized projectile dynamics.
Many have tried to prove there is a rifle/load out there that shoots better at one range than another, and none can.
In short: Its you.
I've read about this topic at length, and also the reverse phenomenon, where you can't shoot a good group at 100, but can hold 1 moa or better at 600 yards.
The answer is there is no known scientific explanation for it. PhD's and scientists understand ballistics, gyroscopic stability, spin drift etc etc etc very well, and have complex models that *very* accurately predict spin-stabilized projectile dynamics.
Many have tried to prove there is a rifle/load out there that shoots better at one range than another, and none can.
In short: Its you.
Re: sub 1 MOA at 100, 4+ MOA at 350???
Could be many things, tell us alittle about your rifle and load.
Could be many things, tell us alittle about your rifle and load.
Re: sub 1 MOA at 100, 4+ MOA at 350???
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: brant</div><div class="ubbcode-body"> Any suggestions? </div></div>
try again , i sucked my frist few trips past 300y
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: brant</div><div class="ubbcode-body"> Any suggestions? </div></div>
try again , i sucked my frist few trips past 300y
Re: sub 1 MOA at 100, 4+ MOA at 350???
over confidence? your saying your a good shooter.. you can shoot 1'' groups at 150 yards.. i can do alot better then that and i suck. youll never hear me say im a good shooter. good shooters let there shooting tell the story. dont go out there expecting to be the baddest man ever to shoot a rifle.
over confidence? your saying your a good shooter.. you can shoot 1'' groups at 150 yards.. i can do alot better then that and i suck. youll never hear me say im a good shooter. good shooters let there shooting tell the story. dont go out there expecting to be the baddest man ever to shoot a rifle.
Re: sub 1 MOA at 100, 4+ MOA at 350???
Could be the load in the rifle. I have had handloads that shot great at 100 but opened up at 300. Vice versa as well. Had loads that shot 1" at 100 but also shot 1" at 300. The key is to find the one that works with both. I only have a 400 yard range and need to shoot out to 1000 at most comps so over the years I have found that if I find a load that shoots good at 100 and 300, the 2 ranges I test loads at, then it will shoot well out to 1000+.
It could also be as mentioned a learning bump. Make sure you are doing everything right as in getting a good solid position and setting the scope up right with parallax. Sometimes little things that don't show up at 100 yards will jump out at you at longer ranges.
Could be the load in the rifle. I have had handloads that shot great at 100 but opened up at 300. Vice versa as well. Had loads that shot 1" at 100 but also shot 1" at 300. The key is to find the one that works with both. I only have a 400 yard range and need to shoot out to 1000 at most comps so over the years I have found that if I find a load that shoots good at 100 and 300, the 2 ranges I test loads at, then it will shoot well out to 1000+.
It could also be as mentioned a learning bump. Make sure you are doing everything right as in getting a good solid position and setting the scope up right with parallax. Sometimes little things that don't show up at 100 yards will jump out at you at longer ranges.
Re: sub 1 MOA at 100, 4+ MOA at 350???
+1 to Rob's comments. I use 100 yards only to get an idea of acceptable velocity and what to look closer at at 400+. All my 1,000 yard and beyond loads are developed at either 420 or 563 (depending upon the wind).
Numerous of my F-Class shooting contemporaries have complained that a good 100 yard load stinks at distance. Hard to say why its so, but it is. But like Rob said if it shoots well at 300 yards or in my case 420 yards, it will generally be gtg at 1,000.
JeffVN
+1 to Rob's comments. I use 100 yards only to get an idea of acceptable velocity and what to look closer at at 400+. All my 1,000 yard and beyond loads are developed at either 420 or 563 (depending upon the wind).
Numerous of my F-Class shooting contemporaries have complained that a good 100 yard load stinks at distance. Hard to say why its so, but it is. But like Rob said if it shoots well at 300 yards or in my case 420 yards, it will generally be gtg at 1,000.
JeffVN
Re: sub 1 MOA at 100, 4+ MOA at 350???
I had a 308 load that kicked ass out to 600 and fell apart at 1000. Barrel change fixed that.
While everything is conditional, at 300 yards it seems to me its the shooter's lack of experience or jinx that can screw the pooch.
Only PROPER prior practise prevents piss poor performance so if after a session or two you don't git 'er done on your own you should most likely seek some in person help.
No one can see you tighten up, anticipate recoil or keep shifting your cheekweld over the computer.
Good luck
I had a 308 load that kicked ass out to 600 and fell apart at 1000. Barrel change fixed that.
While everything is conditional, at 300 yards it seems to me its the shooter's lack of experience or jinx that can screw the pooch.
Only PROPER prior practise prevents piss poor performance so if after a session or two you don't git 'er done on your own you should most likely seek some in person help.
No one can see you tighten up, anticipate recoil or keep shifting your cheekweld over the computer.
Good luck
Re: sub 1 MOA at 100, 4+ MOA at 350???
The phenomenon you describe is not uncommon. Even though none of us like to hear this, it's probably the shooter. However to me this is not a question of who or what is considered a good shooter, but how to improve oneself.
When, I first shoot out to 350 yds, I experienced the same. It has to do with distance exaggerating our inconsistencies and errors. I mean no disresecpt or question your ability, etc with what i'm saying and don't claim to be an expert.
Work on getting solidly behind the rifle and staying on target even after the shot. The recoil with a 300win mag will make this more difficult, don't flinch or anticipate your shot. I think it would be reasonable with practice with a 308win without a muzzle break to be able to stay on target enough after the shot to be able to still see the target in view after the recoil. This can be a gauge as to whether your position is stable and your follow through is good.
Sight picture and breathing are I'mportant especially at further distances. Consistent and appropriate eye relief and cheekwell. Too many factors and techniques to type in detail, but start with those things.
Another thing that I've found that helped me was to spilt the distance. For example, if your groups are good at 100 yds, but open up at 350 yards, try shooting at 200 yards, if they are still not good, try 150 yds...point being is increase in small increments.
The phenomenon you describe is not uncommon. Even though none of us like to hear this, it's probably the shooter. However to me this is not a question of who or what is considered a good shooter, but how to improve oneself.
When, I first shoot out to 350 yds, I experienced the same. It has to do with distance exaggerating our inconsistencies and errors. I mean no disresecpt or question your ability, etc with what i'm saying and don't claim to be an expert.
Work on getting solidly behind the rifle and staying on target even after the shot. The recoil with a 300win mag will make this more difficult, don't flinch or anticipate your shot. I think it would be reasonable with practice with a 308win without a muzzle break to be able to stay on target enough after the shot to be able to still see the target in view after the recoil. This can be a gauge as to whether your position is stable and your follow through is good.
Sight picture and breathing are I'mportant especially at further distances. Consistent and appropriate eye relief and cheekwell. Too many factors and techniques to type in detail, but start with those things.
Another thing that I've found that helped me was to spilt the distance. For example, if your groups are good at 100 yds, but open up at 350 yards, try shooting at 200 yards, if they are still not good, try 150 yds...point being is increase in small increments.
Re: sub 1 MOA at 100, 4+ MOA at 350???
Well first off, while I did say I was a good shooter, I did NOT say I was an excellent shooter or an expert marksman. I guess the word "good" means something different in California. I realize that there are a lot better shooters than me and I know a lot of them, but there a lot worse too. As far as the loads they are just the Remington cheapies from Gander Mtn but I thought that since they shot so well at 100-150yd that they would be good past that as well. Could it be that the bullets aren't very well balanced and they are starting to corkscrew? I definitely need some practice and I think I will load up the .17HMR and do some 200yd shooting to improve m technique. Wish I had a caliber inbetween the two but won't have that kind of money til I get my degree. Another question is how much will barrel heat affect my shot. It is light barrel and I was shooting 3 shot strings then checking my target.
Well first off, while I did say I was a good shooter, I did NOT say I was an excellent shooter or an expert marksman. I guess the word "good" means something different in California. I realize that there are a lot better shooters than me and I know a lot of them, but there a lot worse too. As far as the loads they are just the Remington cheapies from Gander Mtn but I thought that since they shot so well at 100-150yd that they would be good past that as well. Could it be that the bullets aren't very well balanced and they are starting to corkscrew? I definitely need some practice and I think I will load up the .17HMR and do some 200yd shooting to improve m technique. Wish I had a caliber inbetween the two but won't have that kind of money til I get my degree. Another question is how much will barrel heat affect my shot. It is light barrel and I was shooting 3 shot strings then checking my target.
Re: sub 1 MOA at 100, 4+ MOA at 350???
I would look for some quality ammo to try and see what the rifle is capable of. Look into reloading your spent rounds to save money, and dial in a good load.
Also check that you have the parallax adjusted out of your scope.
Keep trying, good luck.
I would look for some quality ammo to try and see what the rifle is capable of. Look into reloading your spent rounds to save money, and dial in a good load.
Also check that you have the parallax adjusted out of your scope.
Keep trying, good luck.
Re: sub 1 MOA at 100, 4+ MOA at 350???
If the gun ain't broke and/or the ammunition is not defective, poor shots at distance is an indication that the shooter simply does not know how to shoot. Being able to get good hits intuitively at SR, makes these shooters believe they know more than they actually do. However, with distance, shooter errors are always unmasked to reveal the truth. Thing is, these shooters, who suddenly can't hit anything at distance, attribute their dilemma to a need for LR training, rather than a need for basic marksmanship training, which they assumed they could bypass. Once again, it's the story of a shooter coming into it all with the notion that a powerful scope mounted to an accurate rifle fitted with a bipod is the ticket to stardom. In every one of these fantasies the equipment has both deceived and distracted the shooter from what is really important to good shooting, which is picture and motor memory development. Those mentally and physically painful concepts however are not as appealing to the would be marksmen as is the possession of good gear.
If the gun ain't broke and/or the ammunition is not defective, poor shots at distance is an indication that the shooter simply does not know how to shoot. Being able to get good hits intuitively at SR, makes these shooters believe they know more than they actually do. However, with distance, shooter errors are always unmasked to reveal the truth. Thing is, these shooters, who suddenly can't hit anything at distance, attribute their dilemma to a need for LR training, rather than a need for basic marksmanship training, which they assumed they could bypass. Once again, it's the story of a shooter coming into it all with the notion that a powerful scope mounted to an accurate rifle fitted with a bipod is the ticket to stardom. In every one of these fantasies the equipment has both deceived and distracted the shooter from what is really important to good shooting, which is picture and motor memory development. Those mentally and physically painful concepts however are not as appealing to the would be marksmen as is the possession of good gear.
Re: sub 1 MOA at 100, 4+ MOA at 350???
It can only be one of a few things....
Breathing
Trigger control
Position behind the rifle
Basically your fundamentals are way off
It's harder to make a gun shoot poorly than it is to make it shoot accurately.
It can only be one of a few things....
Breathing
Trigger control
Position behind the rifle
Basically your fundamentals are way off
It's harder to make a gun shoot poorly than it is to make it shoot accurately.
Re: sub 1 MOA at 100, 4+ MOA at 350???
Before you take that first sip of the hemlock; take a few moments to research the subject of riflescope parallax. You may find something useful in that endeavor.
Greg
Before you take that first sip of the hemlock; take a few moments to research the subject of riflescope parallax. You may find something useful in that endeavor.
Greg
Re: sub 1 MOA at 100, 4+ MOA at 350???
Parallax, stock-weld, butt-to-shoulder, inconsistent elbow placement, who knows, but the shooter himself. And yet, since a correct position may be unnatural for the shooter, without a coach to observe the shooter, this shooter's poor shooting, which is the result of a multitude of errors, is not likely going to be solved here, other than, hopefully, the guy will see the need for some basic marksmanship training.
Parallax, stock-weld, butt-to-shoulder, inconsistent elbow placement, who knows, but the shooter himself. And yet, since a correct position may be unnatural for the shooter, without a coach to observe the shooter, this shooter's poor shooting, which is the result of a multitude of errors, is not likely going to be solved here, other than, hopefully, the guy will see the need for some basic marksmanship training.
Re: sub 1 MOA at 100, 4+ MOA at 350???
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: PinkGunsRSilly</div><div class="ubbcode-body">It can only be one of a few things....
Breathing
Trigger control
Position behind the rifle
Basically your fundamentals are way off
It's harder to make a gun shoot poorly than it is to make it shoot accurately. </div></div>
It could be many of many things, the least likely, breathing.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: PinkGunsRSilly</div><div class="ubbcode-body">It can only be one of a few things....
Breathing
Trigger control
Position behind the rifle
Basically your fundamentals are way off
It's harder to make a gun shoot poorly than it is to make it shoot accurately. </div></div>
It could be many of many things, the least likely, breathing.
Re: sub 1 MOA at 100, 4+ MOA at 350???
It's not the wind.
It could be the loads: I would test loads for a 300WM at 300 and 600, not 100.
At 300+ the skill of the shooter starts to become a noticeable factor. Magnums in lightweight rifles can be hard to shoot well, and trigger problems won't always show up at 150.
Post the target.
It's not the wind.
It could be the loads: I would test loads for a 300WM at 300 and 600, not 100.
At 300+ the skill of the shooter starts to become a noticeable factor. Magnums in lightweight rifles can be hard to shoot well, and trigger problems won't always show up at 150.
Post the target.
Re: sub 1 MOA at 100, 4+ MOA at 350???
The problem as Graham alluded to is heavy recoiling rifles are difficult to control consistently from shot to shot; and, since recoil divergence is angular, and angular errors increase with distance, the magnitude of a shooter's error may be masked at 100 yards. That's to say, distance reveals that the shooter has confused being able to get good hits intuitively with actually knowing how to execute the two firing tasks.
The problem as Graham alluded to is heavy recoiling rifles are difficult to control consistently from shot to shot; and, since recoil divergence is angular, and angular errors increase with distance, the magnitude of a shooter's error may be masked at 100 yards. That's to say, distance reveals that the shooter has confused being able to get good hits intuitively with actually knowing how to execute the two firing tasks.
Re: sub 1 MOA at 100, 4+ MOA at 350???
What I don't get is why does distance matter in exposing bad form... If we were comparing inch's between 100 yards and 500, then it makes sense. But we are comparing MOA. The reason we use MOA is so that it is consistent between distances. If you shoot a 1moa group at 100, it should be a 1moa group at 500, as your form does not change the bullet's trajectory mid-flight. The only thing that change's with distance and midflight is the added wind, which is up to the shooters experience but it doesn't have to do with his form DIRECTLY....
The only other difference's would be the optics/site picture part of things. Is this correct? Either you aren't getting your scope 100% parallax free at that yardage or your not shooting at the exact same spot(since its a smaller target when its far away you might be shooting at a slightly different POA without noticing). I think the latter would be the reason since parallax can be seen if you look for it, and isn't too different once your past 200 yards. So thats why 100 is easier, because your using your high power magnification as a crutch to get you back to your original POA instead of relying on your form to lead the rifle naturally back to its origina POA without having to adjust. So INDIRECTLY this has to do with form, since form is what will bring the rifle back to your original NPA, but things like trigger pull shouldnt have to do with it since a bad trigger pull would show up at shorter distances too. So the thing that needs work is recoil managment.
I've tried to re-think this many ways, and this seems to be the only answer. I have yet to read a post that explains how your trigger pull can magically shift your bullets trajectory after 100 yards. Theoretically, once your bullet leaves the rifle, it should travel at the same minute of angle its entire way.
Sterling, can you chime in on this? You seem to have a wealth of knowledge, and I see you always replying that its form, when someone doesn't shoot well past 100.
What I don't get is why does distance matter in exposing bad form... If we were comparing inch's between 100 yards and 500, then it makes sense. But we are comparing MOA. The reason we use MOA is so that it is consistent between distances. If you shoot a 1moa group at 100, it should be a 1moa group at 500, as your form does not change the bullet's trajectory mid-flight. The only thing that change's with distance and midflight is the added wind, which is up to the shooters experience but it doesn't have to do with his form DIRECTLY....
The only other difference's would be the optics/site picture part of things. Is this correct? Either you aren't getting your scope 100% parallax free at that yardage or your not shooting at the exact same spot(since its a smaller target when its far away you might be shooting at a slightly different POA without noticing). I think the latter would be the reason since parallax can be seen if you look for it, and isn't too different once your past 200 yards. So thats why 100 is easier, because your using your high power magnification as a crutch to get you back to your original POA instead of relying on your form to lead the rifle naturally back to its origina POA without having to adjust. So INDIRECTLY this has to do with form, since form is what will bring the rifle back to your original NPA, but things like trigger pull shouldnt have to do with it since a bad trigger pull would show up at shorter distances too. So the thing that needs work is recoil managment.
I've tried to re-think this many ways, and this seems to be the only answer. I have yet to read a post that explains how your trigger pull can magically shift your bullets trajectory after 100 yards. Theoretically, once your bullet leaves the rifle, it should travel at the same minute of angle its entire way.
Sterling, can you chime in on this? You seem to have a wealth of knowledge, and I see you always replying that its form, when someone doesn't shoot well past 100.
Re: sub 1 MOA at 100, 4+ MOA at 350???
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: timelinex</div><div class="ubbcode-body">What I don't get is why does distance matter in exposing bad form... If we were comparing inch's between 100 yards and 500, then it makes sense. But we are comparing MOA. The reason we use MOA is so that it is consistent between distances. If you shoot a 1moa group at 100, it should be a 1moa group at 500</div></div>
It seems it should be that way, but it isn't....usually. Here is an interesting thread that touches on some of the issues you mention, especially Bryan Litz's comments about the effect of bullet dispersion on <span style="font-style: italic"><span style="font-weight: bold">precision</span></span> at increasing distance:
http://www.snipershide.com/forum/ubbthre...535#Post2246535
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: timelinex</div><div class="ubbcode-body">What I don't get is why does distance matter in exposing bad form... If we were comparing inch's between 100 yards and 500, then it makes sense. But we are comparing MOA. The reason we use MOA is so that it is consistent between distances. If you shoot a 1moa group at 100, it should be a 1moa group at 500</div></div>
It seems it should be that way, but it isn't....usually. Here is an interesting thread that touches on some of the issues you mention, especially Bryan Litz's comments about the effect of bullet dispersion on <span style="font-style: italic"><span style="font-weight: bold">precision</span></span> at increasing distance:
http://www.snipershide.com/forum/ubbthre...535#Post2246535
Re: sub 1 MOA at 100, 4+ MOA at 350???
An inconsistent position means divergent recoil shot to shot. This is about the line of bore from the time the trigger is pulled to the time the bullet has cleared the bore not being controlled consistently. Divergent recoil assures angular error. Angular error increases with distance. This is the sort of error which reveals the shooter does not know all he thinks he knows.
What the shooter's form looks like is not as important as that the position is consistent from shot to shot. Inexperienced shooters make a multitude of errors, in addition to those associated with an inconsistent position. Plus, wind, as well as defective ammunition can contribute to dismal results. Furthermore, an inexperienced shooter may not understand a correct position since it is likely to be, at first, an unnatural one. These factors need to be addressed through a progressive learning process, not one that just lets the shooter have at it. Its too much to juggle.
Long range shooting is about perfecting everything important to good shooting. From where I stand, long range is a destination everyone wants to get to, but few will reach. Most do not have the discipline to perfect their picture and motor memory skills to get to the highest plateaus of long range shooting. Their mindset dismisses the human element to a need for better gear.
An inconsistent position means divergent recoil shot to shot. This is about the line of bore from the time the trigger is pulled to the time the bullet has cleared the bore not being controlled consistently. Divergent recoil assures angular error. Angular error increases with distance. This is the sort of error which reveals the shooter does not know all he thinks he knows.
What the shooter's form looks like is not as important as that the position is consistent from shot to shot. Inexperienced shooters make a multitude of errors, in addition to those associated with an inconsistent position. Plus, wind, as well as defective ammunition can contribute to dismal results. Furthermore, an inexperienced shooter may not understand a correct position since it is likely to be, at first, an unnatural one. These factors need to be addressed through a progressive learning process, not one that just lets the shooter have at it. Its too much to juggle.
Long range shooting is about perfecting everything important to good shooting. From where I stand, long range is a destination everyone wants to get to, but few will reach. Most do not have the discipline to perfect their picture and motor memory skills to get to the highest plateaus of long range shooting. Their mindset dismisses the human element to a need for better gear.
Re: sub 1 MOA at 100, 4+ MOA at 350???
I think we can think this thing to death and still have the problem. Rather than going on a personal witch hunt attempting to figure out what's wrong, I think it makes better sense to drop the Sherlocking and concentrate on what's going on that's <span style="font-style: italic">right</span>.
Whenever I've 'got a problem', I go back to the basics.
I review my shot setup process, and reestablish my prefiring checklist.
Pretty much all of the time, I catch myself glossing over something important, losing patience with the regimen, or allowing fatigue or discomfort to overcome my self discipline.
It may not be the answer, but it's probably a good start toward finding it.
...or sometimes we simply have to back it off a notch, consider the possibility that we're just not in a position to have a good day, and pack it up til the next time.
It's sorta like coming to the range to do things that require precision, finding it's really windy, and going ahead anyway. Everything we do is wasted; if we're being honest with ourselves, anyway...
That's why I always pack the .22LR. At last I can rescue the session and do some wind training.
Practice is only good if we're doing it right; and when we can't, all we're accomplishing is wasting time and ammo, and treating ourselves to a self imposed diet of frustration.
Better to not...
Greg
I think we can think this thing to death and still have the problem. Rather than going on a personal witch hunt attempting to figure out what's wrong, I think it makes better sense to drop the Sherlocking and concentrate on what's going on that's <span style="font-style: italic">right</span>.
Whenever I've 'got a problem', I go back to the basics.
I review my shot setup process, and reestablish my prefiring checklist.
Pretty much all of the time, I catch myself glossing over something important, losing patience with the regimen, or allowing fatigue or discomfort to overcome my self discipline.
It may not be the answer, but it's probably a good start toward finding it.
...or sometimes we simply have to back it off a notch, consider the possibility that we're just not in a position to have a good day, and pack it up til the next time.
It's sorta like coming to the range to do things that require precision, finding it's really windy, and going ahead anyway. Everything we do is wasted; if we're being honest with ourselves, anyway...
That's why I always pack the .22LR. At last I can rescue the session and do some wind training.
Practice is only good if we're doing it right; and when we can't, all we're accomplishing is wasting time and ammo, and treating ourselves to a self imposed diet of frustration.
Better to not...
Greg
Re: sub 1 MOA at 100, 4+ MOA at 350???
Greg, you have basics to go back to. Problem here is the shooter has no basics to go back to.
Greg, you have basics to go back to. Problem here is the shooter has no basics to go back to.
Re: sub 1 MOA at 100, 4+ MOA at 350???
Well if that's true, at least it's not that hard a problem to solve. Some good instruction, and there a jumpstart on the way.
I may be at a point where the basics may not be enough.
Lately my performance has been unacceptably substandard. I really am being forced to think it's not so much a matter of technique as a matter of physique.
After a couple of bouts with the C, some serious and chronic Cardiopulmonary issues, and a dandy left humerus/shoulder joint injury, there's just no way around it. 65 is not supposed to be this kind of a time. I don't seem to be able to wangle a prone or sitting position that is both comfortable and steady.
This is a very frustrating situation. My favorite discipline is F Class (or FV200, to be more exact), and I just can't step up and make the grade anymore. It's become a matter of pain management and so many physical distractions that there don't seem to be any more ways to git 'er done.
I know I try to be a wealth of ideas and moral support, but now it's becoming more like a case of physician, heal thyself.
I'm having trouble figuring out the path from here.
I can still shoot pretty well off the bench, but the BR mindset has never really appealed to me.
What to do...?
Greg
Well if that's true, at least it's not that hard a problem to solve. Some good instruction, and there a jumpstart on the way.
I may be at a point where the basics may not be enough.
Lately my performance has been unacceptably substandard. I really am being forced to think it's not so much a matter of technique as a matter of physique.
After a couple of bouts with the C, some serious and chronic Cardiopulmonary issues, and a dandy left humerus/shoulder joint injury, there's just no way around it. 65 is not supposed to be this kind of a time. I don't seem to be able to wangle a prone or sitting position that is both comfortable and steady.
This is a very frustrating situation. My favorite discipline is F Class (or FV200, to be more exact), and I just can't step up and make the grade anymore. It's become a matter of pain management and so many physical distractions that there don't seem to be any more ways to git 'er done.
I know I try to be a wealth of ideas and moral support, but now it's becoming more like a case of physician, heal thyself.
I'm having trouble figuring out the path from here.
I can still shoot pretty well off the bench, but the BR mindset has never really appealed to me.
What to do...?
Greg
Re: sub 1 MOA at 100, 4+ MOA at 350???
Apply yourself to coaching, for me, it has been more rewarding than shooting.
Apply yourself to coaching, for me, it has been more rewarding than shooting.
Re: sub 1 MOA at 100, 4+ MOA at 350???
After reading the linked post, sterling it seems your saying much of the same that I say here, so not sure why you are disagreeing. You agreed that the angle does not change after it leaves the barrel. I think maybe you are just saying don't worry about why, and just work on form. I agree with that many of us need to work on our basics, but I always want to know the why. I'm curious and thats what makes me successful in other areas of life.
The other post, it seems it all just lead back to that bullets have a certain 'yaw' to them, and while thats correct, that wouldn't explain the phenomenon that people are experienced with different MOA at different ranges. Its like contributing a 3 foot miss to the Coriolis effect. Those graphs are grossly blown out of proportion, and the yaw is not the reason a group would go from .5moa to 2 moa. Bryan Litz himself said, in his book, that the yaw is not a significant factor. ALSO if we were getting that technical, the yaw would effect the POI and not the group size, as the same bullets experience the same yaw and would hit at the same deviation from center because they all travel the same distance.
The following explanation was given:
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">A bullet's dispersion is usually initiated at the muzzle, as a small velocity component that's perpendicular to the intended flight path (up, down, left, or right). If that velocity component results in a miss distance of .25" at 100 yards, you can calculate how much miss distance there will be at 1000 yards by looking at the ratio of flight times.
For example, if the bullet strays .25" at 100 yards, where the flight time is .111 seconds, at 1000 yards, it will have strayed by .25*1.632/.111 = 3.7". 1.632 seconds is the flight time to 1000 yards. Note the bullet does not stray by the 2.5" you would expect by multiplying .25" by 10.
This same logic goes for group sizes as well. If you can shoot a .5" group at 100 yards with your rifle, the best you can expect to do at 1000 is 7.4" under ideal conditions and zero MV variation.</div></div>
While I respect his knowledge of the field, unless he's leaving something out OR I'm missing something, this is just simply incorrect. The velocity of the bullet decreases with time, so its stray from center is logistic at worst and not linear(when dealing with MOA scale and not inches scale). This could explain why groups don't proportionality open up in MOA as fast but not why groups get bigger or get smaller. He's mapping the group size idea to be based on flight time instead of distance, but it depends on distance and not time. The time gets greater for each 100 yard increment because velocity decreases, but velocity does not effect group size that way because all of the same bullets are effected the same way so group stays the same. Real world example. Take ball and throw it forward over a distance, it will not deviate from its path to the left or right.(any curve you put on the ball is more to do with air resistance and spin drift, but again if you put that same curve on that ball throw after throw, it will land in same spot). That ball will travel the first 5 feet much faster than the last 5 feet, but that isn't going to make it all of a sudden deviate left or right. The loss of velocity will make it drop faster or curve more towards the end, BUT with the same exact throw over and over again, the ball WILL land in the same spot. There is no randomness to it.
All bad form, WOULD show up in closer range's as long as your comparing MOA instead of inches, as long as a crutch isn't over compensating for your bad form.
I still think the reason many experience their groups open up at longer ranges is that in shorter ranges the higher magnification is acting as a crutch, and lets you get back to original POA while at longer distances you have to rely on your form to get back to original POA.
While I might not be the greatest shooter, going through engineering has solidly taught me the fundamentals of physics(top of class in all physics classes), air resistance etc.. So unless your talking about SUB-atomic particle's or speeds close to the speed of light, the laws of basic physics all apply.
If your reply is just gonna be "it doesn't matter, just work on your form " then don't bother replying. I already know that its my form thats causing it. This is a discussion to figure out why, and even pinpoint what part is causing it.
Just to be clear I'm not trying to get into a pissing match here. I have drawn a conclusion from everything I've experienced(not as much as most ou guys) ,everything I have read about shooting and my good knowledge of physics. If someone can explain with actual fact's why my explanation is wrong, then I'll gladly be the first to admit that I missed something and was wrong. I'm here to learn and improve, not measure sizes.
After reading the linked post, sterling it seems your saying much of the same that I say here, so not sure why you are disagreeing. You agreed that the angle does not change after it leaves the barrel. I think maybe you are just saying don't worry about why, and just work on form. I agree with that many of us need to work on our basics, but I always want to know the why. I'm curious and thats what makes me successful in other areas of life.
The other post, it seems it all just lead back to that bullets have a certain 'yaw' to them, and while thats correct, that wouldn't explain the phenomenon that people are experienced with different MOA at different ranges. Its like contributing a 3 foot miss to the Coriolis effect. Those graphs are grossly blown out of proportion, and the yaw is not the reason a group would go from .5moa to 2 moa. Bryan Litz himself said, in his book, that the yaw is not a significant factor. ALSO if we were getting that technical, the yaw would effect the POI and not the group size, as the same bullets experience the same yaw and would hit at the same deviation from center because they all travel the same distance.
The following explanation was given:
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">A bullet's dispersion is usually initiated at the muzzle, as a small velocity component that's perpendicular to the intended flight path (up, down, left, or right). If that velocity component results in a miss distance of .25" at 100 yards, you can calculate how much miss distance there will be at 1000 yards by looking at the ratio of flight times.
For example, if the bullet strays .25" at 100 yards, where the flight time is .111 seconds, at 1000 yards, it will have strayed by .25*1.632/.111 = 3.7". 1.632 seconds is the flight time to 1000 yards. Note the bullet does not stray by the 2.5" you would expect by multiplying .25" by 10.
This same logic goes for group sizes as well. If you can shoot a .5" group at 100 yards with your rifle, the best you can expect to do at 1000 is 7.4" under ideal conditions and zero MV variation.</div></div>
While I respect his knowledge of the field, unless he's leaving something out OR I'm missing something, this is just simply incorrect. The velocity of the bullet decreases with time, so its stray from center is logistic at worst and not linear(when dealing with MOA scale and not inches scale). This could explain why groups don't proportionality open up in MOA as fast but not why groups get bigger or get smaller. He's mapping the group size idea to be based on flight time instead of distance, but it depends on distance and not time. The time gets greater for each 100 yard increment because velocity decreases, but velocity does not effect group size that way because all of the same bullets are effected the same way so group stays the same. Real world example. Take ball and throw it forward over a distance, it will not deviate from its path to the left or right.(any curve you put on the ball is more to do with air resistance and spin drift, but again if you put that same curve on that ball throw after throw, it will land in same spot). That ball will travel the first 5 feet much faster than the last 5 feet, but that isn't going to make it all of a sudden deviate left or right. The loss of velocity will make it drop faster or curve more towards the end, BUT with the same exact throw over and over again, the ball WILL land in the same spot. There is no randomness to it.
All bad form, WOULD show up in closer range's as long as your comparing MOA instead of inches, as long as a crutch isn't over compensating for your bad form.
I still think the reason many experience their groups open up at longer ranges is that in shorter ranges the higher magnification is acting as a crutch, and lets you get back to original POA while at longer distances you have to rely on your form to get back to original POA.
While I might not be the greatest shooter, going through engineering has solidly taught me the fundamentals of physics(top of class in all physics classes), air resistance etc.. So unless your talking about SUB-atomic particle's or speeds close to the speed of light, the laws of basic physics all apply.
If your reply is just gonna be "it doesn't matter, just work on your form " then don't bother replying. I already know that its my form thats causing it. This is a discussion to figure out why, and even pinpoint what part is causing it.
Just to be clear I'm not trying to get into a pissing match here. I have drawn a conclusion from everything I've experienced(not as much as most ou guys) ,everything I have read about shooting and my good knowledge of physics. If someone can explain with actual fact's why my explanation is wrong, then I'll gladly be the first to admit that I missed something and was wrong. I'm here to learn and improve, not measure sizes.
Re: sub 1 MOA at 100, 4+ MOA at 350???
to the OP: you didn't give much information about your rifle or ammunition, but it sounds like you're shooting a hunting rifle with factory ammo in 300 win mag. Several problems there: unless you have a brake or a suppressor, especially in a hunting rig, there's going to be enough recoil and muzzle blast to affect most anyone trying to shoot a long string. Second, that same barrel will be more subject to changes as the barrel heats up and it may be rubbing the stock, etc. Third, factory hunting ammo may not neccessary compare to bonafid target ammo that's tuned for your gun. Four, you did not state the scope you're using. The difference in a higher quality scope and mounts will be evident at longer distances, where the quality of the optics will make a difference, that you probably won't see at 100yd. Lastly, shooter technique. Gross errors in sight alignment, breath control or trigger control will be see at 100yds, but those would be really obvious errors. More subtle things like maintaining the same buttstock/shoulder position, cheek weld, head position, NPA, becomes evident at 300yds. But to really shoot well, then minute variables like consistent cheek pressure on the stock, right elbow position, reading conditions have to be addressed. Some of the other comments, especially from SS, however harsh, is correct. Shooting a rifle well, requires good equiptment and a mental discipline to be critical of oneself to find whats wrong and to fix it, whethers its your gear or technique.
to the OP: you didn't give much information about your rifle or ammunition, but it sounds like you're shooting a hunting rifle with factory ammo in 300 win mag. Several problems there: unless you have a brake or a suppressor, especially in a hunting rig, there's going to be enough recoil and muzzle blast to affect most anyone trying to shoot a long string. Second, that same barrel will be more subject to changes as the barrel heats up and it may be rubbing the stock, etc. Third, factory hunting ammo may not neccessary compare to bonafid target ammo that's tuned for your gun. Four, you did not state the scope you're using. The difference in a higher quality scope and mounts will be evident at longer distances, where the quality of the optics will make a difference, that you probably won't see at 100yd. Lastly, shooter technique. Gross errors in sight alignment, breath control or trigger control will be see at 100yds, but those would be really obvious errors. More subtle things like maintaining the same buttstock/shoulder position, cheek weld, head position, NPA, becomes evident at 300yds. But to really shoot well, then minute variables like consistent cheek pressure on the stock, right elbow position, reading conditions have to be addressed. Some of the other comments, especially from SS, however harsh, is correct. Shooting a rifle well, requires good equiptment and a mental discipline to be critical of oneself to find whats wrong and to fix it, whethers its your gear or technique.
Re: sub 1 MOA at 100, 4+ MOA at 350???
OP, Angular error produced by sight misalignment and/or an inconsistent position increases with distance. For me, it only takes an out of place elbow, out of place just a hair, to send a bullet almost an inch off zero at 100 yards. BTW, it's this sort of thing that makes Service Rifle shooting at LR such a difficult task. The shooter pursuing this sort of thing must perfect his sight picture and position consistency through picture and motor memory development beyond what most have the discipline to muster. I only know what I know about this through the experience of it all. And, what's important is basic marksmanship. Just try what has been suggested to you by those who know how to do it. The whys of it all will be understood once you've mastered it all. However, since you're interested, here's the why of it, movement of the rifle from the time the trigger is pulled to the time the bullet clears the barrel produces an angle, as well as an arc between line of bore at rest and line of bore as the bullet clears the muzzle. This movement is minuscule, and if the rifle is controlled consistently through the execution of the two firing tasks, shots go where aimed. If, however, the rifle is not controlled consistently shot to shot from the time the trigger is pulled to the time the bullet clears the barrel, the angle and arc will be less or more than was accounted for through sight adjustment; and, shots will go someplace other than where aimed. Although reducing the angularity is not in and of itself particularly meaningful, reducing its tendency to be inconsistent is important, and is possible when the position is built having a consistent relationship between shooter, gun, and ground, and which is controlled until recoil has ceased. As earlier mentioned, the effects of an inconsistent position is masked at SR, but, at mid-range these effects are always revealed because the errors are indeed angular. Inexperienced shooters blow (forgive the pun) this stuff off to wind not correctly countered. Here's the big picture, for good hits at distance everything that can be perfected needs to be perfected. Perfection is realized through practice.
OP, Angular error produced by sight misalignment and/or an inconsistent position increases with distance. For me, it only takes an out of place elbow, out of place just a hair, to send a bullet almost an inch off zero at 100 yards. BTW, it's this sort of thing that makes Service Rifle shooting at LR such a difficult task. The shooter pursuing this sort of thing must perfect his sight picture and position consistency through picture and motor memory development beyond what most have the discipline to muster. I only know what I know about this through the experience of it all. And, what's important is basic marksmanship. Just try what has been suggested to you by those who know how to do it. The whys of it all will be understood once you've mastered it all. However, since you're interested, here's the why of it, movement of the rifle from the time the trigger is pulled to the time the bullet clears the barrel produces an angle, as well as an arc between line of bore at rest and line of bore as the bullet clears the muzzle. This movement is minuscule, and if the rifle is controlled consistently through the execution of the two firing tasks, shots go where aimed. If, however, the rifle is not controlled consistently shot to shot from the time the trigger is pulled to the time the bullet clears the barrel, the angle and arc will be less or more than was accounted for through sight adjustment; and, shots will go someplace other than where aimed. Although reducing the angularity is not in and of itself particularly meaningful, reducing its tendency to be inconsistent is important, and is possible when the position is built having a consistent relationship between shooter, gun, and ground, and which is controlled until recoil has ceased. As earlier mentioned, the effects of an inconsistent position is masked at SR, but, at mid-range these effects are always revealed because the errors are indeed angular. Inexperienced shooters blow (forgive the pun) this stuff off to wind not correctly countered. Here's the big picture, for good hits at distance everything that can be perfected needs to be perfected. Perfection is realized through practice.
Re: sub 1 MOA at 100, 4+ MOA at 350???
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: timelinex</div><div class="ubbcode-body">
The following explanation was given:
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">A bullet's dispersion is usually initiated at the muzzle, as a small velocity component that's perpendicular to the intended flight path (up, down, left, or right). If that velocity component results in a miss distance of .25" at 100 yards, you can calculate how much miss distance there will be at 1000 yards by looking at the ratio of flight times.
For example, if the bullet strays .25" at 100 yards, where the flight time is .111 seconds, at 1000 yards, it will have strayed by .25*1.632/.111 = 3.7". 1.632 seconds is the flight time to 1000 yards. Note the bullet does not stray by the 2.5" you would expect by multiplying .25" by 10.
This same logic goes for group sizes as well. If you can shoot a .5" group at 100 yards with your rifle, the best you can expect to do at 1000 is 7.4" under ideal conditions and zero MV variation.</div></div>
While I respect his knowledge of the field, unless he's leaving something out OR I'm missing something, this is just simply incorrect.
...
He's mapping the group size idea to be based on flight time instead of distance, but it depends on distance and not time. </div></div>
t,
Thank you for taking the time to provide a well thought out reply. Like you, I'm not looking for a fight, just wanting to discuss the 'why'.
The above quote of mine was (I think) taken from a post on this forum. In my book, you'll find a more complete development of my ideas on dispersion. I'll try to sum up here.
One can describe two basic types of dispersion: those from aiming error, and those that occur from disturbances at the muzzle (static imbalance for example).
Dispersion from aiming error is totally linear, as you describe, for the reason you describe. The bullet is simply flying a straight path. If the miss distance is 1/4" at 100 yards, it will be 2.5" at 1000 yards, etc.
However, the other kind of dispersion which comes from disturbances at the muzzle does not behave this way. Imagine a bullet that has a static imbalance, spinning at 200,000 RPM. The instant the bullet exits the muzzle, it will be 'dispersed' in the direction the CG was moving as it exited the muzzle. In other words, the bullet has a component of lateral velocity (different than simply being imperfectly aimed). For example, let's say this bullet has 2 inches per second of lateral velocity. <span style="font-style: italic">That lateral velocity will result in the bullet being displaced further at long range than at short range.</span> It's true that the velocity magnitude of the bullet slows as it flies downrange. However, it's the main (forward) component of bullet velocity that's being resisted and decreasing the most. In other words, the forward velocity may decrease from 3000 fps to 1200 fps, but the lateral velocity wouldn't slow much from 2 inches per second (.1666 fps).
If my explanation is not adequate, you can refer to these references for other, more mathematically based derivations of bullet dispersion being related to tof and not range:
Modern Exterior Ballistics by Robert McCoy: Chapter 12
Rifle Accuracy Facts by Harold Vaughn: page 170
Harold Vaughn's equation for bullet deflection due to static imbalance is:
sigma = 24*pi*(V/t)*(TOF)*delta
where:
sigma is dispersion in inches
V is muzzle velocity
t is twist rate in inches per revolution
TOF is time of flight in seconds
delta is the CG offset of a bullet in inches.
*typically delta is less than 0.0001" for good bullets.
Other examples of dispersion that would be a function of time of flight are those related to barrel whip or moving platforms (like jerking the trigger).
So you're not wrong in your explanation, but I believe you were only considering one type of dispersion, and not other types.
Looking forward to your thoughts on the subject.
-Bryan
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: timelinex</div><div class="ubbcode-body">
The following explanation was given:
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">A bullet's dispersion is usually initiated at the muzzle, as a small velocity component that's perpendicular to the intended flight path (up, down, left, or right). If that velocity component results in a miss distance of .25" at 100 yards, you can calculate how much miss distance there will be at 1000 yards by looking at the ratio of flight times.
For example, if the bullet strays .25" at 100 yards, where the flight time is .111 seconds, at 1000 yards, it will have strayed by .25*1.632/.111 = 3.7". 1.632 seconds is the flight time to 1000 yards. Note the bullet does not stray by the 2.5" you would expect by multiplying .25" by 10.
This same logic goes for group sizes as well. If you can shoot a .5" group at 100 yards with your rifle, the best you can expect to do at 1000 is 7.4" under ideal conditions and zero MV variation.</div></div>
While I respect his knowledge of the field, unless he's leaving something out OR I'm missing something, this is just simply incorrect.
...
He's mapping the group size idea to be based on flight time instead of distance, but it depends on distance and not time. </div></div>
t,
Thank you for taking the time to provide a well thought out reply. Like you, I'm not looking for a fight, just wanting to discuss the 'why'.
The above quote of mine was (I think) taken from a post on this forum. In my book, you'll find a more complete development of my ideas on dispersion. I'll try to sum up here.
One can describe two basic types of dispersion: those from aiming error, and those that occur from disturbances at the muzzle (static imbalance for example).
Dispersion from aiming error is totally linear, as you describe, for the reason you describe. The bullet is simply flying a straight path. If the miss distance is 1/4" at 100 yards, it will be 2.5" at 1000 yards, etc.
However, the other kind of dispersion which comes from disturbances at the muzzle does not behave this way. Imagine a bullet that has a static imbalance, spinning at 200,000 RPM. The instant the bullet exits the muzzle, it will be 'dispersed' in the direction the CG was moving as it exited the muzzle. In other words, the bullet has a component of lateral velocity (different than simply being imperfectly aimed). For example, let's say this bullet has 2 inches per second of lateral velocity. <span style="font-style: italic">That lateral velocity will result in the bullet being displaced further at long range than at short range.</span> It's true that the velocity magnitude of the bullet slows as it flies downrange. However, it's the main (forward) component of bullet velocity that's being resisted and decreasing the most. In other words, the forward velocity may decrease from 3000 fps to 1200 fps, but the lateral velocity wouldn't slow much from 2 inches per second (.1666 fps).
If my explanation is not adequate, you can refer to these references for other, more mathematically based derivations of bullet dispersion being related to tof and not range:
Modern Exterior Ballistics by Robert McCoy: Chapter 12
Rifle Accuracy Facts by Harold Vaughn: page 170
Harold Vaughn's equation for bullet deflection due to static imbalance is:
sigma = 24*pi*(V/t)*(TOF)*delta
where:
sigma is dispersion in inches
V is muzzle velocity
t is twist rate in inches per revolution
TOF is time of flight in seconds
delta is the CG offset of a bullet in inches.
*typically delta is less than 0.0001" for good bullets.
Other examples of dispersion that would be a function of time of flight are those related to barrel whip or moving platforms (like jerking the trigger).
So you're not wrong in your explanation, but I believe you were only considering one type of dispersion, and not other types.
Looking forward to your thoughts on the subject.
-Bryan
Re: sub 1 MOA at 100, 4+ MOA at 350???
I won't get into the numbers, or TOF discussion, I think it does control an aspect of dispersion, but the shooter has a much bigger influence which is added to dispersion discussed, we see during every single class.
People can generally do well at 100 yards and then immediately start to fall apart at distance, because those errors are magnified by range. It has more time to increase the problem.
After one such discussion on here, we shot this video, simply to see the difference with the same shooter and same rifle who changes their finger position from the pad to the joint. What we found is, at 100 yards, there was no measurable difference across a series of groups, but at 300 yards, we found a 1/2 MOA difference in group size. To complicate matters more, Jacob using the Werewolf in the video actually shot better at 100 yards using the joint over the Pad, but then went on to shoot better at distance using the pad over the joint.
<iframe width="640" height="390" src="http://www.youtube.com/embed/S72ehttwFxw" frameborder="0" allowfullscreen></iframe>
In terms of the trigger, not only is the press important, but the follow through too. Sterling is alluding to this, but he combines it in the overall performance because as he says, even an elbow out place changes the angle at which the rifle recoils. With a bipod and rest it is not so significant as with a sling supported position but his general description is sound. Consistency is the key and any change in consistency will open up the groups.
The rifle is a big tuning fork, once you hit the "go button" or in this case the trigger, the process is just beginning. Most people look at this as the end of the process, feeling they started by lining up the sights and then pressing the trigger when everything looked good to them. At this point they disengage from the rifle. In their mind it is over. The level of disengagement changes, thus effecting the harmonics of the rifle as it is going through the process of firing. Make no mistake, there is a process taking place, and it takes time before the bullet leaves the bore. Our sub-concisious self can absolutely beat that process which is where inconsistency and deviation come from. How you manage the trigger is directly related to how the rifle vibrates, effecting the barrel whip and dispersion Brian is talking about. It is quite common that results found from shooting a rifle locked into a mechanical fixture cannot be reproduced when you take the same rifle and put a human being behind it. The laws aren't changing just being manipulated by the human factor.
I have related story after story here of classes, either government or military where every single shooter has the same weapons system and ammunition, yet the deviation between "dope" at 1000 yards is as much as 2 mils difference in wind correction across the class. We also see a difference in elevation but we'll just discuss horizontal here. This 2 mils can have shooter 1 using 3.5 Mils to hit a target, and shooter 20 needing 1.5 mils to hit the same target under the same conditions. To take this ever further, we took an Accuracy International 300WM and zeroed it using a Lead Sled so the rifle and scope was mechanically zeroed to each other. Letting 10 shooter engage a 1" target at 100 yards with the rifle we found 4" of variance from outside edge to outside edge. Now, I understand these rifles were not zeroed to the shooter, but this shows the shooters level of influence, some hit center, while other left and most right. The Human factor is added to the physics of the bullet flight. Put together with issues in breathing, shoulder pressure, etc, you can also include a vertical dispersion which has nothing to do with velocity changes, but where the barrel is when the bullet exits. Again, that process of firing, if you hold your breath, let it as soon as you push the "go button" thinking you finished the task, the body collapses the barrel rises the strike is now high.
Think of it this way, in order to get 20MOA downrange with a canted base, they only add about 15/1000ths of an inch to a flat base from front to back. So if you move differently 1/1000ths of an inch at the rifle from shot to shot that is potentially 1" added deviation at 100 yards. Do it again at 200 yards and you added even more on top of the physics of dispersion.
Most of the math is designed to work under a vary specific set of circumstances. The human factor is the wildcard which you can add on top of the math.
It is not uncommon to see errors in form appear after 100 yards. It's why we preach fundamentals above all else. Knowing and executing are two different things in this case. It it wasn't we'd all be world class by reading a thread or two.
I won't get into the numbers, or TOF discussion, I think it does control an aspect of dispersion, but the shooter has a much bigger influence which is added to dispersion discussed, we see during every single class.
People can generally do well at 100 yards and then immediately start to fall apart at distance, because those errors are magnified by range. It has more time to increase the problem.
After one such discussion on here, we shot this video, simply to see the difference with the same shooter and same rifle who changes their finger position from the pad to the joint. What we found is, at 100 yards, there was no measurable difference across a series of groups, but at 300 yards, we found a 1/2 MOA difference in group size. To complicate matters more, Jacob using the Werewolf in the video actually shot better at 100 yards using the joint over the Pad, but then went on to shoot better at distance using the pad over the joint.
<iframe width="640" height="390" src="http://www.youtube.com/embed/S72ehttwFxw" frameborder="0" allowfullscreen></iframe>
In terms of the trigger, not only is the press important, but the follow through too. Sterling is alluding to this, but he combines it in the overall performance because as he says, even an elbow out place changes the angle at which the rifle recoils. With a bipod and rest it is not so significant as with a sling supported position but his general description is sound. Consistency is the key and any change in consistency will open up the groups.
The rifle is a big tuning fork, once you hit the "go button" or in this case the trigger, the process is just beginning. Most people look at this as the end of the process, feeling they started by lining up the sights and then pressing the trigger when everything looked good to them. At this point they disengage from the rifle. In their mind it is over. The level of disengagement changes, thus effecting the harmonics of the rifle as it is going through the process of firing. Make no mistake, there is a process taking place, and it takes time before the bullet leaves the bore. Our sub-concisious self can absolutely beat that process which is where inconsistency and deviation come from. How you manage the trigger is directly related to how the rifle vibrates, effecting the barrel whip and dispersion Brian is talking about. It is quite common that results found from shooting a rifle locked into a mechanical fixture cannot be reproduced when you take the same rifle and put a human being behind it. The laws aren't changing just being manipulated by the human factor.
I have related story after story here of classes, either government or military where every single shooter has the same weapons system and ammunition, yet the deviation between "dope" at 1000 yards is as much as 2 mils difference in wind correction across the class. We also see a difference in elevation but we'll just discuss horizontal here. This 2 mils can have shooter 1 using 3.5 Mils to hit a target, and shooter 20 needing 1.5 mils to hit the same target under the same conditions. To take this ever further, we took an Accuracy International 300WM and zeroed it using a Lead Sled so the rifle and scope was mechanically zeroed to each other. Letting 10 shooter engage a 1" target at 100 yards with the rifle we found 4" of variance from outside edge to outside edge. Now, I understand these rifles were not zeroed to the shooter, but this shows the shooters level of influence, some hit center, while other left and most right. The Human factor is added to the physics of the bullet flight. Put together with issues in breathing, shoulder pressure, etc, you can also include a vertical dispersion which has nothing to do with velocity changes, but where the barrel is when the bullet exits. Again, that process of firing, if you hold your breath, let it as soon as you push the "go button" thinking you finished the task, the body collapses the barrel rises the strike is now high.
Think of it this way, in order to get 20MOA downrange with a canted base, they only add about 15/1000ths of an inch to a flat base from front to back. So if you move differently 1/1000ths of an inch at the rifle from shot to shot that is potentially 1" added deviation at 100 yards. Do it again at 200 yards and you added even more on top of the physics of dispersion.
Most of the math is designed to work under a vary specific set of circumstances. The human factor is the wildcard which you can add on top of the math.
It is not uncommon to see errors in form appear after 100 yards. It's why we preach fundamentals above all else. Knowing and executing are two different things in this case. It it wasn't we'd all be world class by reading a thread or two.
Re: sub 1 MOA at 100, 4+ MOA at 350???
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bryan Litz</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: timelinex</div><div class="ubbcode-body">
The following explanation was given:
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">A bullet's dispersion is usually initiated at the muzzle, as a small velocity component that's perpendicular to the intended flight path (up, down, left, or right). If that velocity component results in a miss distance of .25" at 100 yards, you can calculate how much miss distance there will be at 1000 yards by looking at the ratio of flight times.
For example, if the bullet strays .25" at 100 yards, where the flight time is .111 seconds, at 1000 yards, it will have strayed by .25*1.632/.111 = 3.7". 1.632 seconds is the flight time to 1000 yards. Note the bullet does not stray by the 2.5" you would expect by multiplying .25" by 10.
This same logic goes for group sizes as well. If you can shoot a .5" group at 100 yards with your rifle, the best you can expect to do at 1000 is 7.4" under ideal conditions and zero MV variation.</div></div>
While I respect his knowledge of the field, unless he's leaving something out OR I'm missing something, this is just simply incorrect.
...
He's mapping the group size idea to be based on flight time instead of distance, but it depends on distance and not time. </div></div>
t,
Thank you for taking the time to provide a well thought out reply. Like you, I'm not looking for a fight, just wanting to discuss the 'why'.
The above quote of mine was (I think) taken from a post on this forum. In my book, you'll find a more complete development of my ideas on dispersion. I'll try to sum up here.
One can describe two basic types of dispersion: those from aiming error, and those that occur from disturbances at the muzzle (static imbalance for example).
Dispersion from aiming error is totally linear, as you describe, for the reason you describe. The bullet is simply flying a straight path. If the miss distance is 1/4" at 100 yards, it will be 2.5" at 1000 yards, etc.
However, the other kind of dispersion which comes from disturbances at the muzzle does not behave this way. Imagine a bullet that has a static imbalance, spinning at 200,000 RPM. The instant the bullet exits the muzzle, it will be 'dispersed' in the direction the CG was moving as it exited the muzzle. In other words, the bullet has a component of lateral velocity (different than simply being imperfectly aimed). For example, let's say this bullet has 2 inches per second of lateral velocity. <span style="font-style: italic">That lateral velocity will result in the bullet being displaced further at long range than at short range.</span> It's true that the velocity magnitude of the bullet slows as it flies downrange. However, it's the main (forward) component of bullet velocity that's being resisted and decreasing the most. In other words, the forward velocity may decrease from 3000 fps to 1200 fps, but the lateral velocity wouldn't slow much from 2 inches per second (.1666 fps).
If my explanation is not adequate, you can refer to these references for other, more mathematically based derivations of bullet dispersion being related to tof and not range:
Modern Exterior Ballistics by Robert McCoy: Chapter 12
Rifle Accuracy Facts by Harold Vaughn: page 170
Harold Vaughn's equation for bullet deflection due to static imbalance is:
sigma = 24*pi*(V/t)*(TOF)*delta
where:
sigma is dispersion in inches
V is muzzle velocity
t is twist rate in inches per revolution
TOF is time of flight in seconds
delta is the CG offset of a bullet in inches.
*typically delta is less than 0.0001" for good bullets.
Other examples of dispersion that would be a function of time of flight are those related to barrel whip or moving platforms (like jerking the trigger).
So you're not wrong in your explanation, but I believe you were only considering one type of dispersion, and not other types.
Looking forward to your thoughts on the subject.
-Bryan </div></div>
Thanks for chiming in and taking the time to explain it further.
As I said in my post, I'm probably just missing something, and you showed a side to the overall picture that I was missing. I didn't account for the different dispersions as you said.
I did do further digging though, and couldn't find how static imbalances would cause the shift. I don't have the books quoted, but I have found similar texts. It seems that equation is correct, but from the form's that I find it in, it is based on cylindrical cordinates. What I'm getting at there is that imbalances do cause shifts in flight, but they are cylindrical and rotate around an axis, and so they do deviate from the path, but back and forth(because its spinning). So essentially it looks like it's describing the 'yaw' that was talked about earlier and concluded to not cause significant changes.
Here is a source I found on this, click here . You can read through the everything in there, and for those that would rather get to the meat and potatoes, go to page 294 and you will see the illustrations of trajectories caused by static and dynamic imbalances. Both cause the bullet to deviate from its straight path, but only around a center point. The equation's are meant to find where it is in space in relation to that center path at any given time. Thats why time is the factor and not distance, because the phenomenon is internally based only on the object moving and has no relation to the distance it flies or the environment.
LASTLY, assuming the thoughts on dispersion that were mentioned in your post were true, this wouldn't explain most questions anyways. It would explain why someone has exaggerated grouping's at 1000 yards compared to 100 but many of the questions are differences between 100 yards and 200 or 400. Thats when most the 'gurus' step in and say bad form is exaggerated. If you look at flight times between 100 and 200, they are almost identical, at 300 it is .02 seconds off and even by 400 it is only .05 off. This means that a .5 MOA group could possibly open up to a .55 group. Noone complains about this, but rather much bigger differences like .5 going to 1.5.
Someone is definitely missing something, and it could very well be me, since there's no argument that groups consistently open up with new shooters as targets get farther. I'm still jsut trying to get to the bottom of what the actual cause is. So Bryan, maybe you clear up what I'm missing.
Also I appreciate your post Lowlight, and completely agree with you that we can theorize all we want but it won't change the pattern you see with real life expereience.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bryan Litz</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: timelinex</div><div class="ubbcode-body">
The following explanation was given:
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">A bullet's dispersion is usually initiated at the muzzle, as a small velocity component that's perpendicular to the intended flight path (up, down, left, or right). If that velocity component results in a miss distance of .25" at 100 yards, you can calculate how much miss distance there will be at 1000 yards by looking at the ratio of flight times.
For example, if the bullet strays .25" at 100 yards, where the flight time is .111 seconds, at 1000 yards, it will have strayed by .25*1.632/.111 = 3.7". 1.632 seconds is the flight time to 1000 yards. Note the bullet does not stray by the 2.5" you would expect by multiplying .25" by 10.
This same logic goes for group sizes as well. If you can shoot a .5" group at 100 yards with your rifle, the best you can expect to do at 1000 is 7.4" under ideal conditions and zero MV variation.</div></div>
While I respect his knowledge of the field, unless he's leaving something out OR I'm missing something, this is just simply incorrect.
...
He's mapping the group size idea to be based on flight time instead of distance, but it depends on distance and not time. </div></div>
t,
Thank you for taking the time to provide a well thought out reply. Like you, I'm not looking for a fight, just wanting to discuss the 'why'.
The above quote of mine was (I think) taken from a post on this forum. In my book, you'll find a more complete development of my ideas on dispersion. I'll try to sum up here.
One can describe two basic types of dispersion: those from aiming error, and those that occur from disturbances at the muzzle (static imbalance for example).
Dispersion from aiming error is totally linear, as you describe, for the reason you describe. The bullet is simply flying a straight path. If the miss distance is 1/4" at 100 yards, it will be 2.5" at 1000 yards, etc.
However, the other kind of dispersion which comes from disturbances at the muzzle does not behave this way. Imagine a bullet that has a static imbalance, spinning at 200,000 RPM. The instant the bullet exits the muzzle, it will be 'dispersed' in the direction the CG was moving as it exited the muzzle. In other words, the bullet has a component of lateral velocity (different than simply being imperfectly aimed). For example, let's say this bullet has 2 inches per second of lateral velocity. <span style="font-style: italic">That lateral velocity will result in the bullet being displaced further at long range than at short range.</span> It's true that the velocity magnitude of the bullet slows as it flies downrange. However, it's the main (forward) component of bullet velocity that's being resisted and decreasing the most. In other words, the forward velocity may decrease from 3000 fps to 1200 fps, but the lateral velocity wouldn't slow much from 2 inches per second (.1666 fps).
If my explanation is not adequate, you can refer to these references for other, more mathematically based derivations of bullet dispersion being related to tof and not range:
Modern Exterior Ballistics by Robert McCoy: Chapter 12
Rifle Accuracy Facts by Harold Vaughn: page 170
Harold Vaughn's equation for bullet deflection due to static imbalance is:
sigma = 24*pi*(V/t)*(TOF)*delta
where:
sigma is dispersion in inches
V is muzzle velocity
t is twist rate in inches per revolution
TOF is time of flight in seconds
delta is the CG offset of a bullet in inches.
*typically delta is less than 0.0001" for good bullets.
Other examples of dispersion that would be a function of time of flight are those related to barrel whip or moving platforms (like jerking the trigger).
So you're not wrong in your explanation, but I believe you were only considering one type of dispersion, and not other types.
Looking forward to your thoughts on the subject.
-Bryan </div></div>
Thanks for chiming in and taking the time to explain it further.
As I said in my post, I'm probably just missing something, and you showed a side to the overall picture that I was missing. I didn't account for the different dispersions as you said.
I did do further digging though, and couldn't find how static imbalances would cause the shift. I don't have the books quoted, but I have found similar texts. It seems that equation is correct, but from the form's that I find it in, it is based on cylindrical cordinates. What I'm getting at there is that imbalances do cause shifts in flight, but they are cylindrical and rotate around an axis, and so they do deviate from the path, but back and forth(because its spinning). So essentially it looks like it's describing the 'yaw' that was talked about earlier and concluded to not cause significant changes.
Here is a source I found on this, click here . You can read through the everything in there, and for those that would rather get to the meat and potatoes, go to page 294 and you will see the illustrations of trajectories caused by static and dynamic imbalances. Both cause the bullet to deviate from its straight path, but only around a center point. The equation's are meant to find where it is in space in relation to that center path at any given time. Thats why time is the factor and not distance, because the phenomenon is internally based only on the object moving and has no relation to the distance it flies or the environment.
LASTLY, assuming the thoughts on dispersion that were mentioned in your post were true, this wouldn't explain most questions anyways. It would explain why someone has exaggerated grouping's at 1000 yards compared to 100 but many of the questions are differences between 100 yards and 200 or 400. Thats when most the 'gurus' step in and say bad form is exaggerated. If you look at flight times between 100 and 200, they are almost identical, at 300 it is .02 seconds off and even by 400 it is only .05 off. This means that a .5 MOA group could possibly open up to a .55 group. Noone complains about this, but rather much bigger differences like .5 going to 1.5.
Someone is definitely missing something, and it could very well be me, since there's no argument that groups consistently open up with new shooters as targets get farther. I'm still jsut trying to get to the bottom of what the actual cause is. So Bryan, maybe you clear up what I'm missing.
Also I appreciate your post Lowlight, and completely agree with you that we can theorize all we want but it won't change the pattern you see with real life expereience.
Re: sub 1 MOA at 100, 4+ MOA at 350???
I dont think you are considering the mental aspect of shooting. Distance, even 200 yards, has a mental effect on the shooter.
Why do people blow groups at 100 yards, 3 perfect shots in 1 hole, then, round four is blown out of the group, and after the thrill is over that you can't post the group on the internet because the round is blown, you have number five right back into the center of the 3.
Mentally, we do things that effect the shot. Distance, even 200 yards, adds to that, the perspective to the target has changed, the reticle may cover more space changing the sight picture when compared to 100 yards.
The human factor, and how they perceive the shot is very important. So while the TOF hasn't changed much from 100 to 200 yards, how you see the target has now doubled.
Ask yourself, how do people react jumping off a diving board at 5 ft off the water, versus jumping off a diving board 20 ft off the water. Does it change the way they approach it.
I dont think you are considering the mental aspect of shooting. Distance, even 200 yards, has a mental effect on the shooter.
Why do people blow groups at 100 yards, 3 perfect shots in 1 hole, then, round four is blown out of the group, and after the thrill is over that you can't post the group on the internet because the round is blown, you have number five right back into the center of the 3.
Mentally, we do things that effect the shot. Distance, even 200 yards, adds to that, the perspective to the target has changed, the reticle may cover more space changing the sight picture when compared to 100 yards.
The human factor, and how they perceive the shot is very important. So while the TOF hasn't changed much from 100 to 200 yards, how you see the target has now doubled.
Ask yourself, how do people react jumping off a diving board at 5 ft off the water, versus jumping off a diving board 20 ft off the water. Does it change the way they approach it.
Re: sub 1 MOA at 100, 4+ MOA at 350???
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">I dont think you are considering the mental aspect of shooting. Distance, even 200 yards, has a mental effect on the shooter.
Why do people blow groups at 100 yards, 3 perfect shots in 1 hole, then, round four is blown out of the group, and after the thrill is over that you can't post the group on the internet because the round is blown, you have number five right back into the center of the 3.
Mentally, we do things that effect the shot. Distance, even 200 yards, adds to that, the perspective to the target has changed, the reticle may cover more space changing the sight picture when compared to 100 yards.
The human factor, and how they perceive the shot is very important. So while the TOF hasn't changed much from 100 to 200 yards, how you see the target has now doubled.
Ask yourself, how do people react jumping off a diving board at 5 ft off the water, versus jumping off a diving board 20 ft off the water. Does it change the way they approach it. </div></div>
I completely agree, which is what I said in my first post. That it IS bad form. The only difference is I disagree with the reason most give, that the bullet magically deflects after X yards and that exposes the bad form. Its always said that bad form is a compounding error instead of a consistent one(MOA based) in relation to distance, and what I'm saying is that it is consistent its just that the situation has changed(POA can't be distinguished as precisely at farther distances with same magnification).
I hope that makes what I'm trying to say clearer. I agree with the statement, but I disagree with the explanation. I think it is magnification/site alignment acting as a crutch to the bad form, and as you shoot farther the bonus magnification gives becomes gone.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">I dont think you are considering the mental aspect of shooting. Distance, even 200 yards, has a mental effect on the shooter.
Why do people blow groups at 100 yards, 3 perfect shots in 1 hole, then, round four is blown out of the group, and after the thrill is over that you can't post the group on the internet because the round is blown, you have number five right back into the center of the 3.
Mentally, we do things that effect the shot. Distance, even 200 yards, adds to that, the perspective to the target has changed, the reticle may cover more space changing the sight picture when compared to 100 yards.
The human factor, and how they perceive the shot is very important. So while the TOF hasn't changed much from 100 to 200 yards, how you see the target has now doubled.
Ask yourself, how do people react jumping off a diving board at 5 ft off the water, versus jumping off a diving board 20 ft off the water. Does it change the way they approach it. </div></div>
I completely agree, which is what I said in my first post. That it IS bad form. The only difference is I disagree with the reason most give, that the bullet magically deflects after X yards and that exposes the bad form. Its always said that bad form is a compounding error instead of a consistent one(MOA based) in relation to distance, and what I'm saying is that it is consistent its just that the situation has changed(POA can't be distinguished as precisely at farther distances with same magnification).
I hope that makes what I'm trying to say clearer. I agree with the statement, but I disagree with the explanation. I think it is magnification/site alignment acting as a crutch to the bad form, and as you shoot farther the bonus magnification gives becomes gone.
Re: sub 1 MOA at 100, 4+ MOA at 350???
What you are suggesting is a function of eye sight, more so, while certain power magnifications can start to cause issues at distance, we don't see the errors among new shooters based on whether they have a 10X or 22x in most cases. yes, shooting sub moa targets this true, but say a 1 MOA target at 100 using 22x is not going to cause you to lose an extra MOA of accuracy at 200 using it.
If my eyes are bad, which mine are, I can see that being an issue, but I don't have the problem. I am pretty consistent on my fundamentals so my poor eye sight in my right eye is not as big a factor as you suggest, and I rarely use a scope over 16x.
You're statement that POA cant be distinguished is a bit more about sight picture and what you should look for than actual sighting. Iron sight shooters are focusing on the sights not the target which is slightly out of focus. That is form, not function of eye sight, A slightly blurred POA is part of the understanding. If my front sight is clear, my target is not.
What you are suggesting is a function of eye sight, more so, while certain power magnifications can start to cause issues at distance, we don't see the errors among new shooters based on whether they have a 10X or 22x in most cases. yes, shooting sub moa targets this true, but say a 1 MOA target at 100 using 22x is not going to cause you to lose an extra MOA of accuracy at 200 using it.
If my eyes are bad, which mine are, I can see that being an issue, but I don't have the problem. I am pretty consistent on my fundamentals so my poor eye sight in my right eye is not as big a factor as you suggest, and I rarely use a scope over 16x.
You're statement that POA cant be distinguished is a bit more about sight picture and what you should look for than actual sighting. Iron sight shooters are focusing on the sights not the target which is slightly out of focus. That is form, not function of eye sight, A slightly blurred POA is part of the understanding. If my front sight is clear, my target is not.
Re: sub 1 MOA at 100, 4+ MOA at 350???
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">I did do further digging though, and couldn't find how static imbalances would cause the shift. I don't have the books quoted, but I have found similar texts. It seems that equation is correct, but from the form's that I find it in, it is based on cylindrical cordinates. What I'm getting at there is that imbalances do cause shifts in flight, but they are cylindrical and rotate around an axis, and so they do deviate from the path, but back and forth(because its spinning). So essentially it looks like it's describing the 'yaw' that was talked about earlier and concluded to not cause significant changes.</div></div>
This is a good description of the bullet oscillating in free flight. But back up to the point when the bullet first emerges from the muzzle.
While in the muzzle, the bullet is conformed by the barrel to rotate around it's center of form (external surface), not it's center of gravity. When the bullet leaves the muzzle, it's center of rotation <span style="font-style: italic">transitions</span> from center of form, to center of gravity. At this instant is when the velocity component (90 degrees from the direction of travel) is introduced. It's a 'step input' to the bullets trajectory, and happens as the bullet literally flys off on a tangent (the CG's tangent to the axis of rotation). It's like swinging a weight around on a string and the string breaks. Once the initial lateral velocity component is introduced in this transition, the bullet just oscillates around it's center of gravity as you described, not changing it's initial lateral velocity or dispersion rate.
Back to the point of various angular sized groups at different ranges. Whether a group is growing or shrinking in MOA with range, one possible explanation I always offer is parallax. I think often times shooters don't properly adjust their scopes for parallax at all ranges. So you may have a case where the parallax was perfectly dialed out at 100 yards, but out of whack at 200 yards. The sight picture might appear in focus, but the parallax can still be way off causing aiming error that's range dependent.
Not discounting the statements about fundamentals, trigger control, etc. Just offering something else to think about.
-Bryan
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">I did do further digging though, and couldn't find how static imbalances would cause the shift. I don't have the books quoted, but I have found similar texts. It seems that equation is correct, but from the form's that I find it in, it is based on cylindrical cordinates. What I'm getting at there is that imbalances do cause shifts in flight, but they are cylindrical and rotate around an axis, and so they do deviate from the path, but back and forth(because its spinning). So essentially it looks like it's describing the 'yaw' that was talked about earlier and concluded to not cause significant changes.</div></div>
This is a good description of the bullet oscillating in free flight. But back up to the point when the bullet first emerges from the muzzle.
While in the muzzle, the bullet is conformed by the barrel to rotate around it's center of form (external surface), not it's center of gravity. When the bullet leaves the muzzle, it's center of rotation <span style="font-style: italic">transitions</span> from center of form, to center of gravity. At this instant is when the velocity component (90 degrees from the direction of travel) is introduced. It's a 'step input' to the bullets trajectory, and happens as the bullet literally flys off on a tangent (the CG's tangent to the axis of rotation). It's like swinging a weight around on a string and the string breaks. Once the initial lateral velocity component is introduced in this transition, the bullet just oscillates around it's center of gravity as you described, not changing it's initial lateral velocity or dispersion rate.
Back to the point of various angular sized groups at different ranges. Whether a group is growing or shrinking in MOA with range, one possible explanation I always offer is parallax. I think often times shooters don't properly adjust their scopes for parallax at all ranges. So you may have a case where the parallax was perfectly dialed out at 100 yards, but out of whack at 200 yards. The sight picture might appear in focus, but the parallax can still be way off causing aiming error that's range dependent.
Not discounting the statements about fundamentals, trigger control, etc. Just offering something else to think about.
-Bryan
Re: sub 1 MOA at 100, 4+ MOA at 350???
Parallax is definitely misunderstood and often confused with focus... that is the easiest most reasonable explanation of the problem.
Parallax is definitely misunderstood and often confused with focus... that is the easiest most reasonable explanation of the problem.
Re: sub 1 MOA at 100, 4+ MOA at 350???
Thanks for your replies, I think this topic has been throughly explained enough now(to me atleast!)
Thanks for your replies, I think this topic has been throughly explained enough now(to me atleast!)
Re: sub 1 MOA at 100, 4+ MOA at 350???
Timelinex,
I still think you may be wonderin' about why a 1 MOA error at 100 yards is not a 1 MOA error at 300 yards. Am I right? The answer is that while MOA is constant your errors are not. For example, a 1/4 MOA sight adjustment (constant) will always deliver about a 1/4 inch inch effect at 100 yards and about a 3/4 inch effect at 300 yards. However, your position inconsistency might produce shot to shot inconsistencies which are variable, like 1/4 minute, 1/8 minute, 3 minute, etc.
Of course, what ever the cumulative effect at 100 yards, you are still expecting it at 300 yards, yes? But, thing is, you are comparing two stings of fire, one at 100 yards, and another on a different timeline at 300 yards. Only if your 100 and 300 yard groups where shot in real time fired as one string of fire would the error you produce show the results you had expected, assuming no variables and no wind during the external ballistics phase.
Timelinex,
I still think you may be wonderin' about why a 1 MOA error at 100 yards is not a 1 MOA error at 300 yards. Am I right? The answer is that while MOA is constant your errors are not. For example, a 1/4 MOA sight adjustment (constant) will always deliver about a 1/4 inch inch effect at 100 yards and about a 3/4 inch effect at 300 yards. However, your position inconsistency might produce shot to shot inconsistencies which are variable, like 1/4 minute, 1/8 minute, 3 minute, etc.
Of course, what ever the cumulative effect at 100 yards, you are still expecting it at 300 yards, yes? But, thing is, you are comparing two stings of fire, one at 100 yards, and another on a different timeline at 300 yards. Only if your 100 and 300 yard groups where shot in real time fired as one string of fire would the error you produce show the results you had expected, assuming no variables and no wind during the external ballistics phase.
Re: sub 1 MOA at 100, 4+ MOA at 350???
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sterling Shooter</div><div class="ubbcode-body">Timelinex,
I still think you may be wonderin' about why a 1 MOA error at 100 yards is not a 1 MOA error at 300 yards. Am I right? The answer is that while MOA is constant your errors are not. For example, a 1/4 MOA sight adjustment (constant) will always deliver about a 1/4 inch inch effect at 100 yards and about a 3/4 inch effect at 300 yards. However, your position inconsistency might produce shot to shot inconsistencies which are variable, like 1/4 minute, 1/8 minute, 3 minute, etc.
Of course, what ever the cumulative effect at 100 yards, you are still expecting it at 300 yards, yes? But, thing is, you are comparing two stings of fire, one at 100 yards, and another on a different timeline at 300 yards. Only if your 100 and 300 yard groups where shot in real time fired as one string of fire would the error you produce show the results you had expected, assuming no variables and no wind during the external ballistics phase. </div></div>
Right,so sounds like your saying what Im saying. If we put a target at 100 yards and at 300 yards right behind each other, aiming at the 100 our MOA error would stay the same. It's the added distance that your aiming at that messes with your groups(and I was guessing it has to do with site alignment and magnification), and your bad form is exposed.
I didn't discuss it further with my last post, because I figured at this point we were all on the same page but just saying it in different ways.... and just misreading each other.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sterling Shooter</div><div class="ubbcode-body">Timelinex,
I still think you may be wonderin' about why a 1 MOA error at 100 yards is not a 1 MOA error at 300 yards. Am I right? The answer is that while MOA is constant your errors are not. For example, a 1/4 MOA sight adjustment (constant) will always deliver about a 1/4 inch inch effect at 100 yards and about a 3/4 inch effect at 300 yards. However, your position inconsistency might produce shot to shot inconsistencies which are variable, like 1/4 minute, 1/8 minute, 3 minute, etc.
Of course, what ever the cumulative effect at 100 yards, you are still expecting it at 300 yards, yes? But, thing is, you are comparing two stings of fire, one at 100 yards, and another on a different timeline at 300 yards. Only if your 100 and 300 yard groups where shot in real time fired as one string of fire would the error you produce show the results you had expected, assuming no variables and no wind during the external ballistics phase. </div></div>
Right,so sounds like your saying what Im saying. If we put a target at 100 yards and at 300 yards right behind each other, aiming at the 100 our MOA error would stay the same. It's the added distance that your aiming at that messes with your groups(and I was guessing it has to do with site alignment and magnification), and your bad form is exposed.
I didn't discuss it further with my last post, because I figured at this point we were all on the same page but just saying it in different ways.... and just misreading each other.
Re: sub 1 MOA at 100, 4+ MOA at 350???
I think that parallax is clearly at issue when MOA performance is so disparate at two distances. Again, I strongly suggest that shooters make it their business to research and understand parallax and its workings.
There are a few folks who have done their homework about parallax on this site, but when LL speaks to a shooting problem involving optics, it's his words I heed first and formost. I <span style="font-style: italic">know</span> he's done his homework on optics.
Greg
I think that parallax is clearly at issue when MOA performance is so disparate at two distances. Again, I strongly suggest that shooters make it their business to research and understand parallax and its workings.
There are a few folks who have done their homework about parallax on this site, but when LL speaks to a shooting problem involving optics, it's his words I heed first and formost. I <span style="font-style: italic">know</span> he's done his homework on optics.
Greg
Re: sub 1 MOA at 100, 4+ MOA at 350???
This may not be any help. With that said, It becomes exponentially harder to hold MOA (or fractions of MOA) as range increases. My Rem 700 will easily shoot .5 MOA at 100 and I can repeat this regularly. However, I can not shoot 5" groups at 1000 yards or 2.5" groups at 500 yards. .
This may not be any help. With that said, It becomes exponentially harder to hold MOA (or fractions of MOA) as range increases. My Rem 700 will easily shoot .5 MOA at 100 and I can repeat this regularly. However, I can not shoot 5" groups at 1000 yards or 2.5" groups at 500 yards. .
Re: sub 1 MOA at 100, 4+ MOA at 350???
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Flynn</div><div class="ubbcode-body">This may not be any help. With that said, It becomes exponentially harder to hold MOA (or fractions of MOA) as range increases. My Rem 700 will easily shoot .5 MOA at 100 and I can repeat this regularly. However, I can not shoot 5" groups at 1000 yards or 2.5" groups at 500 yards. . </div></div>
I understand what you are saying, yet, holding hard is not pecular to distance. It's inconsistenccy in hold which is unmasked with distance.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Flynn</div><div class="ubbcode-body">This may not be any help. With that said, It becomes exponentially harder to hold MOA (or fractions of MOA) as range increases. My Rem 700 will easily shoot .5 MOA at 100 and I can repeat this regularly. However, I can not shoot 5" groups at 1000 yards or 2.5" groups at 500 yards. . </div></div>
I understand what you are saying, yet, holding hard is not pecular to distance. It's inconsistenccy in hold which is unmasked with distance.
Re: sub 1 MOA at 100, 4+ MOA at 350???
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bryan Litz</div><div class="ubbcode-body">It's true that the velocity magnitude of the bullet slows as it flies downrange. However, it's the main (forward) component of bullet velocity that's being resisted and decreasing the most. In other words, the forward velocity may decrease from 3000 fps to 1200 fps, but the lateral velocity wouldn't slow much from 2 inches per second (.1666 fps).
-Bryan </div></div>
Air resistance vector affects always directly against bullet flying direction. For example lets drop all other forces and consider air resistance only: if bullet velocity vector at the muzzle is:
1000 i + j, where i is the main component and j is lateral component, then launch angle is atan(1/1000) = 0,06 deg.
After bullet velocity has slowed down to half velocity vector is 500 i + 0.5 j, then flying angle is atan(0,5/500)=0,06 deg (still the same).
So I think it is incorrect to say that any lateral velocity component based dispersion can be proportional to flight time.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bryan Litz</div><div class="ubbcode-body">It's true that the velocity magnitude of the bullet slows as it flies downrange. However, it's the main (forward) component of bullet velocity that's being resisted and decreasing the most. In other words, the forward velocity may decrease from 3000 fps to 1200 fps, but the lateral velocity wouldn't slow much from 2 inches per second (.1666 fps).
-Bryan </div></div>
Air resistance vector affects always directly against bullet flying direction. For example lets drop all other forces and consider air resistance only: if bullet velocity vector at the muzzle is:
1000 i + j, where i is the main component and j is lateral component, then launch angle is atan(1/1000) = 0,06 deg.
After bullet velocity has slowed down to half velocity vector is 500 i + 0.5 j, then flying angle is atan(0,5/500)=0,06 deg (still the same).
So I think it is incorrect to say that any lateral velocity component based dispersion can be proportional to flight time.
