1000 yard hits

S

sniperaviator

Sergeant
Full Member
Minuteman
Sep 25, 2010
584
0
64
Colorado
#1
On a whim I just churned this out one late night with little to do. I'm sure it's filled with inaccuracies, but maybe it will incite some interesting discussion.

There are two basic types of rifle inaccuracy. One is variation in group size. The other is deviation from target center. Usually we just talk in group size, but since in tactical competition we are trying to hit a target, say 10" in diameter steel, we need to consider both.

Variation in group size comes from two main sources. Shooter induced variation and equipment induced variation. There is also an environmental factor. Shooter induced variation comes from wiggle caused by the shooters less than perfectly still body. Human muscles are constantly in motion. Equipment induce variation is due to the firearm, barrel, action and ammunition and other equipment being less than perfect and inconsistent from shot to shot.

Deviation from target center is primarily due to environmental factors. We use ballistic charts that are tuned for our air density and dial in windage based on our observation of the wind speed and direction. Any difference in air density
will cause a vertical deviation from target center. Any error in our wind estimation causes a horizontal deviation from target center. Deviation from target center can be summed up by the simple phrase "I am aiming the rifle at the wrong place" (for the environmental conditions).

When I shoot at my 10" steel plate from 1000 yards I know that at 100 yards I have group sizes of 1". That means, in theory, that my group size at 1000 yards should be 10" and I should hit the 10" steel target. However, remember when I am shooting at 100 yards, my group is not perfectly centered on the target. That difference is, let us say, also 1". These two 1" numbers add geometrically to be the square root of 2, which is 1.41 (1 squared plus 1 squared, square rooted). So this translates to 14.1" of deviation at 1000 yards.

No wonder I can't always hit my 10" steel at 1000 yards!
 
#3
Re: 1000 yard hits

Good topic for discussion. I wrote this piece to express the same sentiment:
http://02b0516.netsolhost.com/blog1/?p=76

Your addition of dispersion elements using Root Sum Squares (RSS) is the right way to add random dispersion elements. There's another reason why it's difficult to maintain group sizes at longer ranges.

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.

This dispersion model assumes that aiming error is not a significant part of the dispersion. If there is an aiming error, it will have a perfectly linear effect, meaning .5" at 100 yards translates to 5" at 1000 yards.

-Bryan
 
#4
Re: 1000 yard hits

Bryan,

As an purely hypothetical, shouldn't you also figure in reticle size <span style="font-style: italic">(at least for scoped rifles)</span> in that the aiming error, would always fall behind the thickness of a particular reticle , or are you figuring that as part of your linear aiming error ?

Just wondering out loud how that would increase based on the reticle chosen ?

For the new year, I wish you would include shooter error as being the largest deviation, I get it is implied but too many overlook that aspect of their performance and simply focus on the raw numbers. A small included caveat would suffice.
smile.gif


Merry Christmas.
 
#5
Re: 1000 yard hits

Frank,

Limits in the resolution of sight picture, including reticle size, is certainly considered aiming error and would produce linear dispersion. Naturally a 4X scope with a 2 MOA thick reticle will limit the resolution with which you can aim. At the other extreme is the 60X with fine crosshair that lets you aim between the nuts of a prarie dog at 1500 meters, but has a 6" field of view. Everything's a compromise.

As to your wish, I'll try to be more deliberate with caveats. Maybe I'll just make it my signature line:
"... Don't worry about any of the above until you master the fundamentals"
smile.gif


See you at SHOT?

-Bryan
 
#6
Re: 1000 yard hits

Yes Bryan,

Rifles Only Booth in the LE Section as soon as you come in from the Venetian, I don't have the number in front of me. <span style="font-style: italic"> (Not to far from GAP an isle or two) </span>

Thanks, I like that one... it helps, trust me.

Cheers,
 
#7
Re: 1000 yard hits

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bryan Litz</div><div class="ubbcode-body">60X with fine crosshair lets you aim between the nuts of a prarie dog at 1500 meters </div></div>

Now you're talking
 
#11
Re: 1000 yard hits

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">Bryan,
For the new year, I wish you would include <span style="color: #FF6666">shooter error as being the largest deviation</span>, I get it is implied but too many overlook that aspect of their performance and simply focus on the raw numbers. A small included caveat would suffice.
smile.gif


Merry Christmas.

</div></div>

I prove this to myself every time I try to shoot a tight group -2 touching one 1/2 from the rest and so -consistently inconsistent but sometimes brilliant "occasionally""
 
#12
Re: 1000 yard hits

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bryan Litz</div><div class="ubbcode-body">Frank,

At the other extreme is the 60X with fine crosshair that lets you aim between the nuts of a prarie dog at 1500 meters, but has a 6" field of view. -Bryan </div></div>

that would be a great add for a scope, "a cross hair so fine you can shoot a prarie dog between the nuts at 1500 meters"
 
#13
Re: 1000 yard hits

Mr. Litz,

This is very interesting to me considering the size of the groups I'm capable of shooting with a HUGE .30 cal. magnum.
I'm by no means a mathmatition or an engineer but I can shoot tiny groups and score hits on targets as small a clay bird at 1000 yards SHOT for SHOT as well as ONE moa or better at a mile. Including SEVERAL confirmed ONE SHOT hits on clay birds at a mile over the course of 8 hours.
So, with that said, when I tune my rifle at 100 200 and 250
yards (for a reason) it will shoot in low to mid .200's (at 250 yards).
Now, this is where the math doesn't jive (for me).. When I aim at the 1000 yard IBS target I can see the X most days just fine.
My holding point is in the middle of the X intersection..on clear days or low mirage I should say I have no problem seeing that aiming point in the X with a Night Force 8-32 or 12-42 BR or NXS. The reticule is VERY fine and at ONE MILE I can quarter a clay bird and still see all FOUR corners or pieces of PIE lol.
How is it possible I can shoot 2.00 and 3.00 inches at 1000 yards consitantly with 3-4 bullets TOUCHING if those equations are correct..not to mention they are centered in the target?
I hope this doesn't come off as a challenge to your views and your research. I've read alot of your stuff and I find it interesting to say the least and VERY informative.
Shooting groups at a mile you can cover with your hand or under 1 (one) moa..centered doesn't match the math.
So many tactical shooters over look the importance of a rifle/system that GROUPS well because they are more score oriented..how can you hit something at long range if your rifle doesn't group well? I learned this, say about 20 years ago..when I was die hard ground pounder/prone shooter and would never consider shooting from a bench. Then after getting my ass handed to me in a hat after shooting a 1000 BR match I took it to the next level...no I mean the NEXT level..lol. I incorporate both my diciplines over the years to become a more well rounded longrange shooter and I strive to help others in their quest to do the same.
EVERY new and seasoned tactical/sniper etc. should spend a year or two shooting this type of serious discipline to gain an edge in this great sport and PROFESSION. Most, if not all former Marine Scout Snipers who have shot with us agree after spending the day here. They are seriously amazed and say.."man, if I would've only had this when I was in". That's when you know you've done your job. Or an even a better reward, when he is man enough to shake the civilians hand who just out shot him by 40 or 50 points. Now, I just wish I could get most of them in shape to perform the rest of the task and role as a tactical shooter.

Your thoughts?
 
#14
Re: 1000 yard hits

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tom Sarver</div><div class="ubbcode-body">Mr. Litz,

This is very interesting to me considering the size of the groups I'm capable of shooting with a HUGE .30 cal. magnum.
I'm by no means a mathmatition or an engineer but I can shoot tiny groups and score hits on targets as small a clay bird at 1000 yards SHOT for SHOT as well as ONE moa or better at a mile. Including SEVERAL confirmed ONE SHOT hits on clay birds at a mile

....

Your thoughts?

</div></div>


sleep.gif
 
#15
Re: 1000 yard hits

Well maybe you should try getting some more sleep...or you can stop on out and get a wake call and your questions answered by actually seeing it done...hands on by folks who have done it. I was simply trying to shed some light on your post to help you out. It's not math that is your issue it's your attitude and your shooting ability. If you know so much that my info and FACTS bore you.. then maybe you shouldn't be asking questions if you don't want folks to help you answer them.
 
#16
Re: 1000 yard hits

A clay is 5" right?

I know I can quarter the 6" head on my IPSC steel with my premier 5-25 easily at 1000yds and beyond. What I really want to know is how you can read the wind so well to put 3 shots touching on a regular basis at 1000yds?

Are you waiting for a condition, then rattling the shots off as fast as you can? Or are you taking each shot, singularly, as it's own shot over the course of several minutes?
 
#17
Re: 1000 yard hits

tom,

first, it wasn't my question, so maybe i had no cause to comment.

second, i do believe that you could whoop me whole heartedly with a rifle, i really honestly truely promise i absolutely do. <span style="font-weight: bold">but that is kind of my point</span>. We know who you are.

i qouted your self qualifying statements that i have seen over and over again in your posts. I believe your signature line. no need to tell us what you can do before posting info or asking a question every time. makes me and a few others glaze over....

that is all.
 
#18
Re: 1000 yard hits

Well I respond one more to time to clear MYSELF up.
When I posted to litz's response it was not my intention to boast about what I can do..it's what can be achieved with the right equipment and know how and I was curious to as to way the math added up to what he believes and in NO way do I doubt what he says because I DONT know. See, there..I dont know everything. But what I do know is what I've done with a PRECISION rifle and the math does not add up to me. WHY???? is what I want to know. It's not a challenge to Mr.Litz what so ever, it is a question to him as to why and how. I have my own thoughts as to way and he and I will test our theories when he visits to TVP. As for my signature it's not there to boast. It's there to make folks more comfortable about maybe asking a guy who actually may know something that could help them. If I wanted to boast my mug would be in dozens of advertisements in dozens of magazines. And the dozens of articles out there I had nothing to do with because that is the least of my achievements. Those were just another stepping stone for me. I spend more hours than I should helping folks because I enjoy it and with this thread it could help LOTS of folks but ZZZZ's and such don't help.
I have NO beef with you and as far a whooping your butt with a rifle that has nothing to do with anything. If anything, I would very much like to offer my time to you here at the range to see for yourself and even get behind the trigger to see how well you could do with my stick and loads. Better than you may think I'm sure with some direction and rifle/system that is MADE for that application. No hard feelings man the thread doesnt have to go there...SOUTH.
I was just asking a VERY technical man of knowledge a very technical question and giving him an example as to why I QUESTIONED his theory.
He may be absolutely correct I'm sure. Again, we will test out theories together and post our results. As well as I can shoot I KNOW my rifle and the ENTIRE system still can out shoot me. Maybe somedays the stars line up and it is a .100 rifle when I'm in my bubble. This I have no doubt about. For every reader who is bored with my posts there are 20 e-mails and PM's thanking me for my help and contribution. Hey, I can always go watch tv and chill..lol.
Again, back to exploring MOA accuracy for score and math.
 
#19
Re: 1000 yard hits

Tom,

Back in the 70's they did some testing with Formula 1 drivers Jackie Stewart, Mario Andretti and Ronnie Petersen. They instrumented the car and then had them drive a series of corners for time and then analysed the data output to see what each driver was doing to result in the time he got.

Jackie Stewart was the smoothest and by just a little bit, the slowest. Mario was in the middle, but the anomaly was Ronnie Peterson. The instrumentation showed that there was NO WAY he should be able to do what he does with a car. (Tragically he was killed in a race incident just a few weeks later. I saw it live on TV. RIP).

There are some things in life that I believe cannot be quantified by a formula or an equation... at least not with the limited understanding we might have at the time. Remember that for the longest time the greatest minds believed the Earth was flat. We are constantly learning and when we think we know it all....

Bryan is a brilliant guy but will probably be the first to tell you that his models are not necessarily good for all circumstances. He learning as he goes along too. Tom... you and your performances are at the far end of the bell curve. It doesn't surprise me at all that they are not consistent with our understanding of the way things work. But then again, how many people put the level of preparation into themselves, their equipment and their craft as you do?

In every generation there is someone in a given field that stretches our understanding there, makes us rethink the rules, and better understand what's going on. Just be thankful that you're the guy doing the stretching rather than the guy trying to figure it out!

John
 
#20
Re: 1000 yard hits

very good discussion from all sides here but,Im wondering about another variance i deal with at 1000 yds. mirage, heck the 6 inch black ring on my 25 inch diameter gong moves all over the place,I can see the target fine but where is it really? I just let it kinda dance around the cross till i think im where it is, any of this making sense? as for quartering a clay at 1 mile, well my zeiss 6.5x20 aint gonna get me there, nightforce must be the ticket. just a reality check on the way I see the long range game.As for me I have enough problems with "simple" variables, not to mention high powered math problems
 
#22
Re: 1000 yard hits

Ok, to answer thought one, seeing a orange clay bird at one mile with a N/F 8-32 NXS NPR1 is no problem. I would bet your S&B could see it better IF you had the SAME reticule. At that time S&B did not have a cross hair thin enough for my liking. S&B is just slightly better and MORE clear glass. But, I can still see the bird no sweet...if mirage isn't too crazy.
As for 3 shots touching it has happened alot. And even more accurate to be fair to the readers most holes on alot of good targets are 2-3 holes within 0-3 inches. Some much better.
I pick my condition for about the last 3 minutes of a sight in period. Then yes, I let them rip. Some call it spray and prey but that is hardly an accurate statement. In SOME cases I can shoot much TIGHER groups if I run them fast. Instinct takes over and there is no time to let human error take effect. This is an art form of shooting and must be practiced and honed PERFECTLY to be effective.
Can I read wind well enough? Would you like a modest answer? Then yes I can. I would hope so after all this time. Vern Harrison is a great friend of mine. Talk about a chess match. He is one of the best. High power shooters that I train admit they have NO clue when I train them in this atmosphere. My shooters will attest to my wind reading skills or better yet I will give you a free class if you come to one of our shoots. As for taking one shot singularly yes, that is how I shoot my tactical rifle. I guess that's the only way I could obtain several 120 scores and a couple 140's on the Intimidator. Or in the 100's in a ONE shot ONE kill match on the Intimidator. Like our TOP shooter Karl/Van has learned.
Listen guys, in no way are my posts exaggerated. I'm just stating facts and our shooters here at TVP see it all the time..every weekend.
It can be done. MOST shooters will never reach this level of accuracy and skill. That's why I try and help them and years later they either aquire it or they don't. It's about 20% that do reach it.
Some go even further..again..like Karl. Which motivates other shooters who don't become envious or jealous, they become more involved and serious about their training.
Mike Tyson said before alot of his fights he was going to knock out his challenger between 1&3 rounds. And after doing this so many times people got bored and wanted him to just get beat because he became a threat to some folks envy meter. Once your surrounded by enough hate it will wear on you and finally topple you.
There is an old saying, "If you can't beat them, join them".
Our memberships are $50.00 per year. A very small price to pay to become one of the best. Or at best it will make a believer out of you.
 
#24
Re: 1000 yard hits

The way I see it its comparing apples to oranges.

Sniperaviator says: math for 1 moa rifle shows on average it should group roughly 14.1 inches at 1000 yards.

Tom Sarver says: my .2 moa rifle groups consistently tighter at 1000 yards than 100 yards.

If this were a discussion on blackjack, sniperaviator would say the house usually has a 2% edge over the player (you lose $.02 for every $1 you bet). Then Tom Sarver claims he consistently wins at blackjack.

Apples to oranges guys!
 
#25
Re: 1000 yard hits

I sell and promote N/F. But S&B is better more clear glass.
The difference between a Z51 corvette and a Z06. Most drivers don't know the difference. N/F is great, S&B would be better if they had thinner reticules. I NOW I believe they do. On good days, normally certain temperature evenings, I can see .30 cal. hole in the paper with a 8-32 or 12-42 easy. My eye doctor informed me I have 20/15 vision too..that helps. But they can be seen buy others too..if the conditions are right. Heck, on a good day we can see clay birds at a mile with our naked eyes here at TVP. So it's not that big of a deal.

As for haters, I just want to help. And I forgive when something is taken out of txt. If a guy wants to challenge me or slam me then I'm old and cranky some days and I'm only human. I just want to get along and make new friends in our shooting world. I have no secrets and I will share my knowledge. I have LOTS of room to grow. That's why I invited Mr. Litz to join me in a day or two of shooting beyond a 1000 yards. We WILL certainly entertain each other and I'm certain we will learn from each other and then share what we've learned with you folks. I think we should all try to be more nice to each other and not get so defensive or pissy about this stuff. We're all here for a reason. We all share this earth. Man thinks he is so smart but so did the cave man when he discovered fire. We are still hillbillies, sorry Momma, compared to what's to come and what's really out there.

I have something I want to share with you guys.

Question #1. What is the 2nd. oldest form of technolgy on earth?
Answer.. FIRE.
The cave man discovered it, then perfected it and began to cook meat. Then the brain became smarter and more intellegent as time progressed because of the protien the meat supplied. All of the other cave men who was not aware of this (fire) thought it was some sort of GOD like power and if you had it you were to be feared. As time went on more and more cave men learned the technique and when it became common knowledge they forgot WHO discovered it and perfected it and they didn't need him anymore.

Question # 2. What is the number one oldest form of technology?
Answer- Throwing rocks/projectiles.
Ever stop and think how is it you can walk out side and throw a baseball to your son or daughter and it lands perfectly in their glove no matter how far away they are? Ever turn and toss something to someone in a blink of an eye and it there..in their hands with precision? Why is this? Because before there was fire, again the cave man needed to eat. He could'nt out run some mammels or furbearing animals but he could pick up a rock and throw it with speed and enough force to shorten the chase.
Just think...at one time ONE INDIVIDULE got so pissed because he was starved and he could catch that damn rabbit (or whatever they had back then lol) that he was SO frustrated he bent over and picked up a rock and threw it and KILLED the little guy. The rabbit surely jumped up about 3 feet after getting nailed in the head and died instantly as it fell to the ground. Now, humor me..imagine the look on this dudes faces. Again, ANOTHER first...a light bulb went off in his head...hmm..he thought wow...that's how we need to do this from now on. Then came the spear...then the bow...then the gun.
Hang on back up...still to this day only about 1% OUT OF BILLIONS of our so called intellegent people walking around on this modern day planet knows how to start a fire..without matches. Now, how smart are we? Not so much. Even with all my and OUR skill and knowledge we are still only cave men...compared to what coming.
I bet in their spare time when not being chased by hungry preditors cave men had rock throwing contests..I guarantee they did. The winner got to pick the 20 caves woman he wanted to keep him warm that night...Hey!! another light bulb...except for me this time..theres a prize we can hand out at sniper matches!
In all seroiousness it's only been about 40 years since Mr. Hathcock roamed the planet hunting and killing bad guys at great distances that we wouldn't even considered using in a sniper match today.
We have'nt really came that far guys...compared to aircraft..jet fighters and such. We are still cavemen when it comes to rifle and until we get our heads together and quit bitchn at each other and doubting each other we will stay there.
Mr. Litz has broke thru to alot of folks. So have I, so have others.
We can have fun with what we share in this great sport, that's what seperates us from animals...even the cave man knew that.
 
#27
Re: 1000 yard hits

When I first met Tom Sarver,I thought this is cool. This guy built a range within driving distance of me. I can try this 1000 yard thing. If I like it,things will be alright. Tom was hosting a .308 only match. I got my ass handed to me by a 9 year old boy that weekend(great shooting J.P.,I will never forget that.). At the end of the weekend I was hooked. I learned alot that weekend. I started it all on bench #10 there.

This past weekend I was back on bench #10 again with my AR10. I sat there and I thought about the things I have seen and learned at Thunder Valley through the years. Theres been alot.

Tom made mention of clay pigeons at a mile. I will confirm the story. A few years back there was the "Fall Foilage Tour" in Coshocton,Ohio. It was something made for people to see what was available in Tom's county. Thunder Valley was one of the stops. Tom had invited me to attend and show off my rifle. I talked about the range and what is available at Thunder Valley to the guests. They came in busloads. I was suprised to see all the people. Anyway,Tom had a demonstration going for the people that attended. Every hour on the hour Tom would shoot a clay pigeon at one mile. The pigeons were set up in a line. Tom hit them left to right,one shot,one an hour. At that point I knew what kind of shooter my friend is.

I thought I should pay attention to what he is saying about this long range sport. I never did say anything about that day to Tom,except that I froze my ass off. I read what is posted on here,and I know some people do not believe what Tom Sarver is saying or have their doubts. The fact is,it happened.


van
 
#28
Re: 1000 yard hits

BigMahi,

maybe to touch a little more on my theory of the math and why it is what it is...

My rifle when tuned properly and I do my job will shoot .200 or under at 100 yards and 250 yards.

But, ever hear of this before? Bullets settle or fall asleep at 300 or so? A rifle may shoot 1 moa at 100 but .5 at 250 yards? Well..what if mine does that...shrinks even more at distance say like 400 or so...where I've NEVER tuned it to see.
What if it's because the bullets going 200-300 fps faster than it was intended to shoot so you have a NEW accuracy node?
This is where and why Iasked Mr. Litz the question. Maybe..just maybe...all the combinations of things just cause some strange new results. So..now I'm going to slightly sound like I'm boasting again but I'm not...it's the only way I can explain it to make sense of it. If it isn't true..my theory..then why in the 40 year history of the sport has no one ever shot GROUPS this small (consistantly)or a GROUP as small as 1.397" ? Some reasons are the cartridge design and componants used and rifle design. Those are some reasons.. the others..well..we will see.

 
#29
Re: 1000 yard hits

Tom,

I'll go with the bullet 'going to sleep' theory as part of it. I used to poo-poo that theory as well. I could never understand why I'd shoot a 1" group @ 100 and 500 either. Now I go along with the theory as I believe it does have some effect.

Another thing was brought up about the race car drivers. If you've ever gotten the chance to run some practice laps at a track in a really fast car you'd know that once you get up to speed, so does your mind. It's like you said your instincts take over. You see every thing so clearly even though it's going by twice as fast as it ever did for you. Slow down to 70 mph and it's like your crawling. I'm thinking the same thing happens with a rifle. I know there's days I can go out and nail everything. 5-6 1" groups @ 300 with 2-3 different rifles. They are good rifles but not cut from the same quality as what you have. Nor do I have the glass you do. But, what I do is mentally splitting hairs. I use the left side of the crosshair instead of the center, or right depending on what I "feel" what the wind is doing. Your mind is just instinctively problem solving this based on the tools you have and what you know they can do. You are just taking them to their full capability.

Along that line there is one other theory I'll run past you. I know you use a 8-32x and 12-42x scope(s) for this extreme shooting. But some days (and ranges) they just don't seem to be enough. It's a little easier to explain when using a ten power. You run out of magnification to super-accurately pinpoint the shot placement you want. What happens then is you start using the scope to give you a mental sight picture instead of finding a precision point to put the crosshairs on. You know like when you fired your M16 rifle and how you center the post in the rear aperture and then that together on the target. You can't see the target as well as the front sight. But, with all that alignment and not even being able to clearly see the target you often put tight groups together. I've done that with numerous rifles. Put a one-half inch group together and not even be able to barely see more than the bold 6" orange squares with the 2" bold orange square in the middle of that. Somewhere in your mind you leave off the fine focus between your eye and brain and go to a "reference focus"
 
#31
Re: 1000 yard hits

Just so I understand, I read somewhere that the bullet initially flies in a corkscrew pattern (like a soap suds spiraling down a drain) for the first few hundred yards or so. So this notion of "falling asleep" basically refers to the point where the bullet loses just enough energy so that it goes into a stable flight (I'm thinking like a glider), hence tighter moa at longer distances correct?

If so, then whats the next issue that arises in this context? would it be when the bullet destablilizes as it becomes subsonic?
 
#32
Re: 1000 yard hits

Big<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BigMahi</div><div class="ubbcode-body">Just so I understand, I read somewhere that the bullet initially flies in a corkscrew pattern (like a soap suds spiraling down a drain) for the first few hundred yards or so. So this notion of "falling asleep" basically refers to the point where the bullet loses just enough energy so that it goes into a stable flight (I'm thinking like a glider), hence tighter moa at longer distances correct?

If so, then whats the next issue that arises in this context? would it be when the bullet de-stablilizes as it becomes subsonic? </div></div>

BigMahi,

How I like to explain it is like if you have a top that you hand spin. At first all the energy of all the side forces it took to generate the spin have to be dissipated. That's why if you take a top and spin it at first you see it going kind of wild. Then it settles down and if on a super flat plane looks like it isn't even moving. That is until gravity and air resistance take over and the top loses stability again and starts wobbling. Eventually falling down. Gears from an old clock really work well for tops to prove this. The big difference is that a top is stable in one place and the bullet starts moving through the air at anywhere from 2500-3000 fps and that creates a force the bullet will eventually not overcome as well.

As far as coming through the transonic range, picture the top totally stable, then touch it on one side. The rotational forces of the top make it want to move at about 90 degrees from the point of contact. The sonic 'boom' created by the bullet is actually a pressure wave. As it catches up to the bullet (the bullet falls back to it) the force created is like your finger touching the top. It wants to send the bullet out of stability.

Every bullet is affected by this. Some a lot more, some a lot less. Much of that depends on factors such as initial stabiliy, inherent stability, time in the transonic range, bullet length, diameter, and shape, etc.



<span style="color: #3333FF">Edit:

In one of Tom other posts:
http://www.snipershide.com/forum/ubbthre...261#Post2267261

He talks about getting the rifle, bullet and case as true to each other as is humanly possible. This helps eliminate the "side forces" that create the wobblyness of a bullet when immediately fired. The type of bullet used and the twist and the true-ness of the entire system all contribute to stability. I know it sounds boring but benchrest guys get unbelievable stability from their bullets as they leave their barrels. The problem is their bullets don't have long range capability. They give that up for the stability factor of consistently shooting groups in the .1's or lower.</span>

<span style="color: #6600CC">Edit II:

One of the big reasons bullets will restabilize is again just like when you touch your finger to the top it wants to wobble. Once that force has been dissipated, if there is still enough rotational inertia on the bullet it will re-stabilize below the speed of sound.</span>
 
#33
Re: 1000 yard hits

You need to record your average group size, not your best. If someone shoots 100 3 shot groups, one of those is likely to be a very small group. Human tendency is to grab that paper and stick it in the wallet. And think that is representative of YOUR groups size. Maybe a good idea from a self esteem point of view, and even a motivatioinal point of view. But it's not an accurate indicator of how this guys shoots.

As for the theory not matching the real world results. Just like rifles and groups, theories aren't perfect either. The theory is there so we can PREDICT (and possibly improve upon) what will happen. It's just one part of what is going on.

If bonafide, reliable results don't match the theory, the theory may be wrong. Scrap it and find a new rifle 'er theory.
 
#35
Re: 1000 yard hits

lol a-hull

so what im not understanding is some comments like

"so thats why i can shoot 1 inch at one hundred and then again at five hundred."

how would that be possible, because if you are grouping 2 inches at three hundred, isn't it angularly impossible to group back down to anything less than two inches beyond that range?

this is a "once the damage (having an enlarged group)" is done, isn't it impossible to regian ground MOA speaking?

like i could see having a bullet "go to sleep at 300" and your group size at three hundred being 3 inches. then at four hundred because the bullet has gone to sleep the group is only slightly larger than three inches as opposed to getting linearly worse like a group that is not in its "sleep/stable" range.
 
#36
Re: 1000 yard hits

The reason for missing is simple, the shooter did not understand where the barrel was pointed, or how to point the barrel in the direction needed for a good hit. Since most folks can hit relatively big and close targets intuitively, they consider the miss at LR to be peculiar to LR, or wind; however, the bad result at LR is usually nothing more than unmasked angular error, which was not noticed at a shorter distance. BTW, knowing where the barrel is pointed accounts for a consistent position, and sight alignment, as well as properly countering for wind, temperature, drag, and gravity.
 
#37
Re: 1000 yard hits

Bodies in motion do tend to oscillate. Its POSSIBLE that a bullet's trajectory could be a sinusoidal oscillation, transposed on top of a straight line (or even parabolic line) angular deviation. I don't know if bullets really do that, but I think it could be investigated by radar trajectory analysis.
 
#38
Re: 1000 yard hits

Mr. Sarver,

Your question about group sizes was addressed in Bryan's book "Applied Ballistics". I also have noted a similar situation with a rifle of mine that shoots .75" at 100 and 1.5" at 500 on a consistent basis. The short answer in the book is parallax error.

The "going to sleep" theory will not explain a shrinking dispersion, which isn't actually happening at all anyhow. There is a stabilization that takes place, but as the book mentions the majority of this was measured to take place within feet not hundreds of yards.

I hope this helps. I'm sure Bryan can shed more light on that observation. If I remember I may try to find that part of the book, and offer some more of his insights.
 
#39
Re: 1000 yard hits

In addition to parallax, angular error is about an inconsistent position between shots, which produces recoil divergence, or a novel angularity between the bore at rest and bore at bullet exit. Bullets are something else, buy what you believe are good ones, and then, test 'em.
 
#40
Re: 1000 yard hits

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: armymedic.2</div><div class="ubbcode-body">lol a-hull

so what im not understanding is some comments like

<span style="font-weight: bold">"so thats why i can shoot 1 inch at one hundred and then again at five hundred."

how would that be possible, because if you are grouping 2 inches at three hundred, isn't it angularly impossible to group back down to anything less than two inches beyond that range?
</span>
<span style="color: #3333FF">Notice the groups SIZE doesn't shrink. The dispersion of the groups shrink as distance grows. Again, not about only angles but about flight characteristics. That will move a bullet off is center of axis but not it's initial vector.</span>

this is a "once the damage (having an enlarged group)" is done, isn't it impossible to regian ground MOA speaking?

like i could see having a bullet "go to sleep at 300" and your group size at three hundred being 3 inches. then at four hundred because the bullet has gone to sleep the group is only slightly larger than three inches as opposed to getting linearly worse like a group that is not in its "sleep/stable" range.

</div></div>

That is because the bullet didn't move at an angle to the previous or consecutive shots. An unstable bullet isn't going to fly true. It does however want to follow the vector set for it as it left the barrel. Meaning that just like all the highpower guys say, The bullet goes where the barrel points. It is not just a case of parallax being off. Although that is often the case. If the bullets always followed exactly where the barrel went then all bullets would shoot the same from all barrels. And groups sizes would all be in the .1's

As far as shooter position being off I will agree, fundamentals are key. From the prone position and especially from any modified position. What Tom Sarver speaks of though is different. Shooting from a bench that is adjusted to the shooter, pretty much means a shooter goes into his relay shooting from a fundamentally sound position. Everything is all there, you just step in, get yourself set, and pull the trigger when you see the right conditions. Although, I (and I've seen others) have been guilty of getting out of good position when the third or fourth round is going downrange.
I've shot a fair amount of short range bench rest. What I really like about it is the fact that it allows you to seriously look at your equipment. Take yourself out of the equation. With the exception of calling the wind. Which it allows you to really focus on.
I know some of you think that benchrest shooting is boring. Same hole time after time. But, just like any discipline if you are truly striving for the maximum then it remains a challenge. It will never be a challenge to you if don't have the equipment and focus to shave off .010"s from .100" groups. The struggle is as much back in the machine shop as it is up on the line.

 
#41
Re: 1000 yard hits

This is what the bullet flight path looks like-
fig20.gif


Recently, i designed and tested a bullet at all distances from 200yds -1000yds. The bullet was only JUST stable and the group sizes consistently shrank in an almost linear fashion from 6MOA @ 200yds to 2 MOA @ 1000yds.

The "bullet going to sleep theory" is a proven FACT not a theory. The rate at which this motion "goes to sleep" depends on many things, but it eventually damps out over time provided the bullet is dynamically stable, and usually damps to sufficiently negligable levels within 300 yards- for a well balanced, well stablized bullet.

There are 2 "arms" in the coning motion, a fast arm and slow arm, you can see the effect of both in the above image.

Factors which effect this motion are bullet length, spin rate/velocity, to cut along story shot, the bullet shape/design as someone mentioned earlier.

The long nose flat base bullets alot of the long range benchrest shooters use (including tom sarver?) damp this precessional yaw faster due to their lack of a boattail and therfore better inherrant stability. They also tend to have a lower initial yaw angle upon passing the mach cloud and muzzle exit. This is why they typically get better accuracy than a boat tail VLD bullet, and as tom says "i only need enough BC to get the job done...accuracy is king"




 
#42
Re: 1000 yard hits

These threads usually just make my head hurt. I shot 1KBR for a couple years and experienced these anomalies on a regular basis. I started out developing loads at 100yds and I was having some trouble, quite a bit actually. I was shooting the 30 BooBoo and the chronograph told me I had the load but the group size at 100 was hovering around 1MOA. I was green as a granny smith so I decided to just shoot that load come what may. When I went to practice with the load at 500yd I was shocked to learn the load was now .5MOA. It was a boringly consistent pigeon buster at 1000. I talked it over with some guys at the match and I heard several theories including the "sleeping bullet",this just made my head hurt worse. How can a bullet start out squirrely then straighten up and fly right? I know it happens and I will stay tuned for a more definative answer. Meanwhile, being a flat earth kind of guy, I believe that evil humours are eventually flung from the nose of the projectile thus allowing true flight
wink.gif
 
#44
Re: 1000 yard hits

All Noobs,

Don't allow your head to hurt over something which, if it's working, does not need to consume you. Inspect your bullets and shoot some to confirm they are indeed match grade. From there, it's just sight alignment and trigger control. Everything else supports those two principles.

For the best results, learn to shoot using a peep sight, and practice your position until it's vice like using a loop sling, as well as consistent between shots to a molecular level. Do this and you will discover that the scope, bipod, and bench serve mostly to distract shooters from becoming super marksmen. These aids, if not recognized for their limitations, will collectively deceive you into believing you actually know something about good shooting, when, in fact the only thing you know is how to execute the firing tasks to hit targets which can be hit intuitively in conditions you set and control.

Don't get me wrong, BR is fine for BR competition and for those learning to concentrate on the principles of marksmanship; but, don't kid yourself about it meaning you know how to shoot. Shooting with something like a Service Rifle with the intent of zero displacement can help you reach the highest plateaus as it requires more overall marksmanship skill than what most people on the planet have any thought of mustering. The practice for such is just too mentally and physically painful to keep most folks interested for long. If it were not for the rewards of winning in NRA and CMP competitions, I'd doubt any would be interested today. At any rate, with the Service Rifle, a shooter with desire can come to understand everything important to good shooting, to be able to get good hits on any identifiable target at any distance/condition the bullet is still traveling nose-on. And, BTW, that's the only thing about the bullet, while shooting, that may concern you. Once the bullet becomes erratic and begins to tumble end over end, marksmanship is meaningless.
 
#45
Re: 1000 yard hits

At what point did anyone question the value and importance of marksmanship skill in a general sense?

A simple discussion behind the factors influencing real world group sizes at varying distances is what is taking place. This discussion has led us to a point that brings marksmanship skill OUT OF THE QUESTION. Why? Well if the physics and mechanics were not a SIGNIFICANT factor here, more so than marksmanship skill, group sizes would ALWAYS get WORSE the further from the target you get, no exceptions, wouldnt they!

in reality we often see the opposite...

So how does in certain circicumstances the same load, same rifle, same shooter, same conditions, <span style="text-decoration: underline">consistently</span> group tighter in angular measurement @ 300yds compared with 100yds? So would you mind explaining to us, how is it that ones marksmanship skill is causing this to happen? And why not offer an explaination of why you shouldnt consider teh appropriate type of bullet best suited to your intended application, afterall they all fly point first dont they?
 
#46
Re: 1000 yard hits

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: groper</div><div class="ubbcode-body">

So how does in certain circicumstances the same load, same rifle, same shooter, same conditions, <span style="text-decoration: underline">consistently</span> group tighter in angular measurement @ 300yds compared with 100yds? So would you mind explaining to us, how is it that ones marksmanship skill is causing this to happen? And why not offer an explaination of why you shouldnt consider teh appropriate type of bullet best suited to your intended application, afterall they all fly point first dont they?</div></div>

Your assumption that everything is the same is flawed. If everything were indeed the same there would be zero displacement. Since the rifle and ammunition are not as prone to inconsistency as the shooter, marksmanship is what we all should concentrate on, instead of this gobblygook which takes us off task.

BTW, angular error always increases with distance, it's the law, you know, physics.
 
#47
Re: 1000 yard hits

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sterling Shooter</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: groper</div><div class="ubbcode-body">

So how does in certain circicumstances the same load, same rifle, same shooter, same conditions, <span style="text-decoration: underline">consistently</span> group tighter in angular measurement @ 300yds compared with 100yds? So would you mind explaining to us, how is it that ones marksmanship skill is causing this to happen? And why not offer an explaination of why you shouldnt consider teh appropriate type of bullet best suited to your intended application, afterall they all fly point first dont they?</div></div>

Your assumption that everything is the same is flawed. If everything were indeed the same there would be zero displacement. Since the rifle and ammunition are not as prone to inconsistency as the shooter, marksmanship is what we all should concentrate on, instead of this gobblygook which takes us off task.

BTW, angular error always increases with distance, it's the law, you know, physics.</div></div>

I don't think the point of this discussion is gobbledygook. For the sake of the discussion I'll give some standards that we can maybe move forward from.

1. Shooter is trained in all aspects of shooting fundamentals.
2. Shooter applies these fundamentals.
3. Shooter achieves higher than average scores in competitions. Assume he is in the top 10% of either high power competition and/or tactical competition and does it professionally. Again, fundamentals are sound and adhered to.

4. Then shooter wants to know why his groups are a possible .5 MOA at basic zero of 100 yds. And, while group size remains the same or nearly as small, is achieving groups .2 or .3 MOA at ranges of 500-700 yds.

Note:

Sterling Shooter,

There is no question the imagined shooter in this case (could be any one of us) understands completely the importance of the fundamentals. What he is looking for is reasons why accuracy seems to improve with range. Group sizes either remain the same size or grow, but do not grow proportionately with each extended range shot at.
 
#48
Re: 1000 yard hits

I wonder about a lot of things, but the only thing I wonder about when shooting is where to trouble shoot when my shot call and strike are not right-in-there. The physics of it all is in my basis of understanding so that I do not need to ponder it.
 
#49
Re: 1000 yard hits

I've never believed in the notion that a bullet will go to sleep and somehow divert back to a path which enables a proportionately smaller group to be shot at longer ranges. Angular error cannot decrease with distance and in any modern, accurate bolt-gun using quality ammunition, stabilisation of a projectile must occur within a few meters of exiting the muzzle.

Perhaps 100 yd/m groups are not a shooters forte, or they are most often shot at the beginning of a shooting session, when people have not yet 'switched on' - the 'cold shooter' syndrome, per se. Perhaps the rifle/ammo combo is capable of much tighter groups at 100 yd/m than the shooter can deliver, so the platform potential is unrealised. Then, for a multitude of reasons,the shooter is more locked into his/her shooting at longer ranges - better concentration on principles of marksmanship, more warmed-up, etc., which sees the production of some relatively smaller groups at these longer ranges.

I know personally that I don't always shoot as well at 100m as I do at the longer ranges.

Whilst I find the physics interesting, as Sterling has alluded to, it is easy to get bogged down, or overcook this a bit. Plenty of other distractions (read; variables to consider) when you're behind the rifle.
 
#50
Re: 1000 yard hits

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: sandwarrior</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sterling Shooter</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: groper</div><div class="ubbcode-body">

So how does in certain circicumstances the same load, same rifle, same shooter, same conditions, <span style="text-decoration: underline">consistently</span> group tighter in angular measurement @ 300yds compared with 100yds? So would you mind explaining to us, how is it that ones marksmanship skill is causing this to happen? And why not offer an explaination of why you shouldnt consider teh appropriate type of bullet best suited to your intended application, afterall they all fly point first dont they?</div></div>

Your assumption that everything is the same is flawed. If everything were indeed the same there would be zero displacement. Since the rifle and ammunition are not as prone to inconsistency as the shooter, marksmanship is what we all should concentrate on, instead of this gobblygook which takes us off task.

BTW, angular error always increases with distance, it's the law, you know, physics.</div></div>

I don't think the point of this discussion is gobbledygook. For the sake of the discussion I'll give some standards that we can maybe move forward from.

1. Shooter is trained in all aspects of shooting fundamentals.
2. Shooter applies these fundamentals.
3. Shooter achieves higher than average scores in competitions. Assume he is in the top 10% of either high power competition and/or tactical competition and does it professionally. Again, fundamentals are sound and adhered to.

4. Then shooter wants to know why his groups are a possible .5 MOA at basic zero of 100 yds. And, while group size remains the same or nearly as small, is achieving groups .2 or .3 MOA at ranges of 500-700 yds.

Note:

Sterling Shooter,

There is no question the imagined shooter in this case (could be any one of us) understands completely the importance of the fundamentals. What he is looking for is reasons why accuracy seems to improve with range. Group sizes either remain the same size or grow, but do not grow proportionately with each extended range shot at.</div></div>

I assumed we already assumed this. Why don't we just say the rifle is mounted in a vise, to erase human error, and simply concentrate on the ballistics.
 
You must log in or register to reply here.

Similar threads

E
URSA 3000 Yard Challenge (2025) - Announcement
Replies
0
Views
94
ELR researcher
E
U
100 yard accuracy not translating at further distance
Replies
36
Views
875
Cody S
Cody S
P
Steel Target Range Setup
Replies
10
Views
427
FOS373
F
U
Range Report Level of Accuracy in "Leveling a Scope"
Replies
4
Views
292
USMC22
U
C
What am I doing wrong? POI shift in positional shooting
Replies
8
Views
292
cliffy110
C
Top Bottom
Back
Home
Forums
Merch
Alerts