I was shooting some steel last night at 350 yards with my 308. I was hitting just where I should at first. The wind picked up from about 2 o'clock angle at about 15mph. After adjusting for windage, my shots started going low even though I did not adjust elevation. Is it possible that the increase in distance/TOF due to the windage adjustment cause it the bullet to drop more?
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Advanced Marksmanship Can windage affect elevations adjustment?
- Thread starter larbhills
- Start date
Re: Can windage affect elevations adjustment?
Yes. See the reference to "aerodynamic jump" in this reference:
http://www.appliedballisticsllc.com/index_files/Extending_Max_Range.pdf
Yes. See the reference to "aerodynamic jump" in this reference:
http://www.appliedballisticsllc.com/index_files/Extending_Max_Range.pdf
Re: Can windage affect elevations adjustment?
How large (in MOA) was the POI variation?
With a right hand twist (like most barrels have) the bullet should move UP (not down) with wind coming from 2:00.
Perhaps is something else, some vertical component of the wind, etc.
How large (in MOA) was the POI variation?
With a right hand twist (like most barrels have) the bullet should move UP (not down) with wind coming from 2:00.
Perhaps is something else, some vertical component of the wind, etc.
Re: Can windage affect elevations adjustment?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: TiroFijo</div><div class="ubbcode-body">How large (in MOA) was the POI variation?
With a right hand twist (like most barrels have) the bullet should move UP (not down) with wind coming from 2:00.
Perhaps is something else, some vertical component of the wind, etc. </div></div>
It came out to about 2 MOA. Due to trees and terrain it is definitely possible that there was a vertical component to the wind.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: TiroFijo</div><div class="ubbcode-body">How large (in MOA) was the POI variation?
With a right hand twist (like most barrels have) the bullet should move UP (not down) with wind coming from 2:00.
Perhaps is something else, some vertical component of the wind, etc. </div></div>
It came out to about 2 MOA. Due to trees and terrain it is definitely possible that there was a vertical component to the wind.
Re: Can windage affect elevations adjustment?
If it was 2 MOA then the POI variation wasn't due to gyroscopic effects + side wind. Coming fron no lateral wind component to 15 mph from 2:00, the effect would be much smaller, around 0.3 MOA and it would be the reverse (up), if you have a right hand twist.
If it was 2 MOA then the POI variation wasn't due to gyroscopic effects + side wind. Coming fron no lateral wind component to 15 mph from 2:00, the effect would be much smaller, around 0.3 MOA and it would be the reverse (up), if you have a right hand twist.
Re: Can windage affect elevations adjustment?
Your scope could be canted. Therefore its not tracking level when you dial windage, leading to vertical POI shift as well.
A ladder test would rule this out.
Your scope could be canted. Therefore its not tracking level when you dial windage, leading to vertical POI shift as well.
A ladder test would rule this out.
Re: Can windage affect elevations adjustment?
The canting would have to be HUGE to change POI 2.0 MOA.
With a 308 you need about 2.0 MOA to correct a 15 mph 2:00 wind at 350 yds, so to effect a 2.0 vertical variation the cant angle would be close to 45º (and you would need to dial about 2.8 MOA).
The canting would have to be HUGE to change POI 2.0 MOA.
With a 308 you need about 2.0 MOA to correct a 15 mph 2:00 wind at 350 yds, so to effect a 2.0 vertical variation the cant angle would be close to 45º (and you would need to dial about 2.8 MOA).
Re: Can windage affect elevations adjustment?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: TNT</div><div class="ubbcode-body">did the lighting change? </div></div>
Nope. The wind came up, I dialed some windage and started hitting low. There is a small chance (maybe more than a small chance) that it was operator error.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: TNT</div><div class="ubbcode-body">did the lighting change? </div></div>
Nope. The wind came up, I dialed some windage and started hitting low. There is a small chance (maybe more than a small chance) that it was operator error.
Re: Can windage affect elevations adjustment?
Just curious, what type of scope is it? New, used, new to you? How many rounds have you shot, while looking through this scope? Last question, what was your windage correction?
Just curious, what type of scope is it? New, used, new to you? How many rounds have you shot, while looking through this scope? Last question, what was your windage correction?
Re: Can windage affect elevations adjustment?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: larbhills</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: TNT</div><div class="ubbcode-body">did the lighting change? </div></div>
Nope. The wind came up, I dialed some windage and started hitting low. There is a small chance (maybe more than a small chance) that it was operator error. </div></div>
Did your position change (either your cheekweld and/or your pressure on the rifle)? Its refreshing to see the humble remark regarding the most likely piece of the puzzle to have the affect described-that being the loose but behind the trigger.....
My rifle can shoot sub-moa all day, me.....not so much
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: larbhills</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: TNT</div><div class="ubbcode-body">did the lighting change? </div></div>
Nope. The wind came up, I dialed some windage and started hitting low. There is a small chance (maybe more than a small chance) that it was operator error. </div></div>
Did your position change (either your cheekweld and/or your pressure on the rifle)? Its refreshing to see the humble remark regarding the most likely piece of the puzzle to have the affect described-that being the loose but behind the trigger.....
My rifle can shoot sub-moa all day, me.....not so much
Re: Can windage affect elevations adjustment?
When a bullet is flying in no wind, it is flying straight on its front to back axis. When the bullet is affected by a side wind, the rear of the bullet has a larger surface area than the front, so the bullet turns nose-in towards the direction the wind is coming from. The bullet is now "dirty" compared to its flight with no wind effect, therefore decreasing its efficiency as it moves through the air. This causes the bullet's speed to decay at a greater rate, increases the time of flight, and lowers the point of impact.
When a bullet is flying in no wind, it is flying straight on its front to back axis. When the bullet is affected by a side wind, the rear of the bullet has a larger surface area than the front, so the bullet turns nose-in towards the direction the wind is coming from. The bullet is now "dirty" compared to its flight with no wind effect, therefore decreasing its efficiency as it moves through the air. This causes the bullet's speed to decay at a greater rate, increases the time of flight, and lowers the point of impact.
Re: Can windage affect elevations adjustment?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: _9H</div><div class="ubbcode-body">When a bullet is flying in no wind, it is flying straight on its front to back axis. When the bullet is affected by a side wind, the rear of the bullet has a larger surface area than the front, so the bullet turns nose-in towards the direction the wind is coming from. The bullet is now "dirty" compared to its flight with no wind effect, therefore decreasing its efficiency as it moves through the air. <span style="font-weight: bold">This causes the bullet's speed to decay at a greater rate, increases the time of flight, and lowers the point of impact. </span></div></div>
May I ask where do you get this from? There are other more important factors at play, take a look at Bryan Litz explanation here:
http://www.snipershide.com/forum/ubbthre...rue#Post1712302
"when the bullet enters a crosswind, it's forced to realign it's nose (weathervane) into the oncoming air flow. When the bullet's nose turns, there is a gyroscopic reaction which results in a predictable precession pattern. The result of this process is a vertical 'jump', caused by the net effect of the bullets precession 'steering' it up or down based on twist and wind direction. The key here is to understand that the vertical deflection is a 'jump', which happens within tens-of-yards from the muzzle. Once the jump has been established, it's a fixed angular deflection for the rest of the trajectory.
Let's examine the consequence of the above statement. Let's say a bullet has .6" of wind deflection at 100 yards in a 10 mph crosswind. Also, let's say that the bullet has a stability factor that results in .4 MOA of vertical jump from that crosswind. At 100 yards, the deflection angle will be 35 degrees (atan(.42/.6). Now go to 200 yards. The wind deflection at 200 yards is now 2.7", and the vertical angle of deflection is still .4 MOA. So the angle of deflection at 200 yards is only 18 degrees.
Take this out to 1000 yards where the horizontal wind deflection is 94", and the angle of deflection is now only 2.6 degrees. The vertical deflection is .4 MOA all the way (because it was determined close to the muzzle) but the horizontal effect of that crosswind increases much more, thus yielding a shallower angle of deflection at the longer ranges."
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: _9H</div><div class="ubbcode-body">When a bullet is flying in no wind, it is flying straight on its front to back axis. When the bullet is affected by a side wind, the rear of the bullet has a larger surface area than the front, so the bullet turns nose-in towards the direction the wind is coming from. The bullet is now "dirty" compared to its flight with no wind effect, therefore decreasing its efficiency as it moves through the air. <span style="font-weight: bold">This causes the bullet's speed to decay at a greater rate, increases the time of flight, and lowers the point of impact. </span></div></div>
May I ask where do you get this from? There are other more important factors at play, take a look at Bryan Litz explanation here:
http://www.snipershide.com/forum/ubbthre...rue#Post1712302
"when the bullet enters a crosswind, it's forced to realign it's nose (weathervane) into the oncoming air flow. When the bullet's nose turns, there is a gyroscopic reaction which results in a predictable precession pattern. The result of this process is a vertical 'jump', caused by the net effect of the bullets precession 'steering' it up or down based on twist and wind direction. The key here is to understand that the vertical deflection is a 'jump', which happens within tens-of-yards from the muzzle. Once the jump has been established, it's a fixed angular deflection for the rest of the trajectory.
Let's examine the consequence of the above statement. Let's say a bullet has .6" of wind deflection at 100 yards in a 10 mph crosswind. Also, let's say that the bullet has a stability factor that results in .4 MOA of vertical jump from that crosswind. At 100 yards, the deflection angle will be 35 degrees (atan(.42/.6). Now go to 200 yards. The wind deflection at 200 yards is now 2.7", and the vertical angle of deflection is still .4 MOA. So the angle of deflection at 200 yards is only 18 degrees.
Take this out to 1000 yards where the horizontal wind deflection is 94", and the angle of deflection is now only 2.6 degrees. The vertical deflection is .4 MOA all the way (because it was determined close to the muzzle) but the horizontal effect of that crosswind increases much more, thus yielding a shallower angle of deflection at the longer ranges."
Re: Can windage affect elevations adjustment?
The guy's name escapes me - a top benchrest shooter from Texas that is also an airline pilot. Came from an Precision Shooting magazine article many years back. Not gonna dig through them and find it.
The guy's name escapes me - a top benchrest shooter from Texas that is also an airline pilot. Came from an Precision Shooting magazine article many years back. Not gonna dig through them and find it.
Re: Can windage affect elevations adjustment?
wow whole lotta science to explain what is probably shooter error...or a scope issue.
I get it use science and avoid blaming the nut behind the bolt, it's a good strategy when you really think about it.
<span style="font-style: italic">For future reference as a new shooter you're better off screwing up the trigger over your breathing and throwing the shot to the right, you'll get twice the scientific help. </span>
wow whole lotta science to explain what is probably shooter error...or a scope issue.
I get it use science and avoid blaming the nut behind the bolt, it's a good strategy when you really think about it.
<span style="font-style: italic">For future reference as a new shooter you're better off screwing up the trigger over your breathing and throwing the shot to the right, you'll get twice the scientific help. </span>
Re: Can windage affect elevations adjustment?
Agree, as usual (...and it happens to all of us) shooter error is the most probable cause.
Agree, as usual (...and it happens to all of us) shooter error is the most probable cause.
Re: Can windage affect elevations adjustment?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ubet</div><div class="ubbcode-body">Just curious, what type of scope is it? New, used, new to you? How many rounds have you shot, while looking through this scope? Last question, what was your windage correction? </div></div>
Scope is a brand new Bushnell Elite 3200 5-15 Tactical. I have about fifty down range with this scope and it has been doing fine. Adjustments have been precise and repeatable. Adjustment in elevation have not shown any inadvertant change in windage.
I agree that it was probably shooter error but the only thing that puts a monkey wrench in that is that I shot a nice group of three shots. Just not where they were supposed to go.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ubet</div><div class="ubbcode-body">Just curious, what type of scope is it? New, used, new to you? How many rounds have you shot, while looking through this scope? Last question, what was your windage correction? </div></div>
Scope is a brand new Bushnell Elite 3200 5-15 Tactical. I have about fifty down range with this scope and it has been doing fine. Adjustments have been precise and repeatable. Adjustment in elevation have not shown any inadvertant change in windage.
I agree that it was probably shooter error but the only thing that puts a monkey wrench in that is that I shot a nice group of three shots. Just not where they were supposed to go.
Re: Can windage affect elevations adjustment?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: _9H</div><div class="ubbcode-body">The guy's name escapes me - a top benchrest shooter from Texas that is also an airline pilot. Came from an Precision Shooting magazine article many years back. Not gonna dig through them and find it.
</div></div>
Gene Beggs, also known for his aerobatic flying. Saved many lives developing his SPIN Recovery technique.(Power off,let go of the stick and step on the HARD rudder-rotation stops,pull up,avoiding the stall and add power.)
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: _9H</div><div class="ubbcode-body">The guy's name escapes me - a top benchrest shooter from Texas that is also an airline pilot. Came from an Precision Shooting magazine article many years back. Not gonna dig through them and find it.
</div></div>
Gene Beggs, also known for his aerobatic flying. Saved many lives developing his SPIN Recovery technique.(Power off,let go of the stick and step on the HARD rudder-rotation stops,pull up,avoiding the stall and add power.)
Re: Can windage affect elevations adjustment?
There is a good explanation/discussion of wind effecting vertical over on long range hunting. 4th or 5th post down is a chart compiled by Speedy Gonzales a very well known benchrest shooter/ gunsmith type guru. you can right click on them and save them as jpegs for closer study if you're inclined. If someone knows how to post them as pictures it might be helpful to the group
http://www.longrangehunting.com/forums/f17/wind-very-humbling-55691/
There is a good explanation/discussion of wind effecting vertical over on long range hunting. 4th or 5th post down is a chart compiled by Speedy Gonzales a very well known benchrest shooter/ gunsmith type guru. you can right click on them and save them as jpegs for closer study if you're inclined. If someone knows how to post them as pictures it might be helpful to the group
http://www.longrangehunting.com/forums/f17/wind-very-humbling-55691/
Re: Can windage affect elevations adjustment?
Well, since internal, external, and terminal ballistics are within the purview of science, not considering it makes marksmanship development kinda difficult. After all, most anything we engage in is begun with a basis of understanding about physical law.
Well, since internal, external, and terminal ballistics are within the purview of science, not considering it makes marksmanship development kinda difficult. After all, most anything we engage in is begun with a basis of understanding about physical law.
Re: Can windage affect elevations adjustment?
Well like anything, there are "reasons" and then there are "reasons'... I highly doubt science is going to explain a 2 MOA difference at 350 yards. The time of flight is entirely too short to cause that type of effect. I am all about the science of things and go to great lengths to learn it...
Take the link above Sterlings' post on Long Range Shooting...
It incorrectly states that Humidity cause the bullet impact to go down because it increases the air density. Increased Humidity in fact does the opposite, the air is "less dense" because water in its vapor form is lighter than air. But here we have people supposedly in the know regarding the science of Long Range shooting repeating this ( and I don't mean the person who posted the link) why because it was written... Humid air feeling more dense is strictly a human reaction to it.
Then below that paragraph you have the old rule of thumb on Temperature which is often repeated... a 20 degree change will move the bullet impact 1 MOA. But it doesn't say where ? 1 MOA at 100, 1 MOA At 350... where is that 1 MOA change is the question. That was written back in the 60's more than likely and today we have better barrels, bullets and powders so that often repeated rule is full of holes.
Science is great, but using it to explain poor shooting is a poor use of it.
Vague and incomplete references are just that...
Well like anything, there are "reasons" and then there are "reasons'... I highly doubt science is going to explain a 2 MOA difference at 350 yards. The time of flight is entirely too short to cause that type of effect. I am all about the science of things and go to great lengths to learn it...
Take the link above Sterlings' post on Long Range Shooting...
It incorrectly states that Humidity cause the bullet impact to go down because it increases the air density. Increased Humidity in fact does the opposite, the air is "less dense" because water in its vapor form is lighter than air. But here we have people supposedly in the know regarding the science of Long Range shooting repeating this ( and I don't mean the person who posted the link) why because it was written... Humid air feeling more dense is strictly a human reaction to it.
Then below that paragraph you have the old rule of thumb on Temperature which is often repeated... a 20 degree change will move the bullet impact 1 MOA. But it doesn't say where ? 1 MOA at 100, 1 MOA At 350... where is that 1 MOA change is the question. That was written back in the 60's more than likely and today we have better barrels, bullets and powders so that often repeated rule is full of holes.
Science is great, but using it to explain poor shooting is a poor use of it.
Vague and incomplete references are just that...
Re: Can windage affect elevations adjustment?
Lowlight,
Would it be worth asking the question about how we should understand those rules now or is that something that will be addressed in the online training?
I am fine either way, but now you've got me very interested.
Thanks,
RB
Lowlight,
Would it be worth asking the question about how we should understand those rules now or is that something that will be addressed in the online training?
I am fine either way, but now you've got me very interested.
Thanks,
RB
Re: Can windage affect elevations adjustment?
Low Light, Sterling;
So what are your "rules of thumb"? I dont keep a Log but I shoot to 650 several times a week and I can tell you that my elevation can vary a couple clicks depending on Temp (temps can change here 40* in a day here), and wind speed and direction, or mirage. Aside from a much warmer day I cant give you a scientific answer as to why, but its noticeable.
Do you notice consistent elevation changes in classes (or matches in sterling's case) as the day heats ups and/or the wind picks up/changes? If everyone in the class is making small adjustments (a click or two not a minute or two) that takes the user error out of the equation. What are you seeing in classes every day? Thanks
Low Light, Sterling;
So what are your "rules of thumb"? I dont keep a Log but I shoot to 650 several times a week and I can tell you that my elevation can vary a couple clicks depending on Temp (temps can change here 40* in a day here), and wind speed and direction, or mirage. Aside from a much warmer day I cant give you a scientific answer as to why, but its noticeable.
Do you notice consistent elevation changes in classes (or matches in sterling's case) as the day heats ups and/or the wind picks up/changes? If everyone in the class is making small adjustments (a click or two not a minute or two) that takes the user error out of the equation. What are you seeing in classes every day? Thanks
Re: Can windage affect elevations adjustment?
Absolutely your dope changes from day to day... we see it everyday in every class.
Your DOPE is just that... Data On Previous Engagement and doesn't mean what you shot last week will be exactly the same as this weekend, especially if you track it very closely. With a steel plate like a Larue, which is 12X22 at 650 yards that is quite a bit of elevation you can hide within the target, 3.3 MOA worth of difference. If you shoot paper you can track it better, but that still may change. Temperature, Barometric pressure will change it a bit, but that doesn't always translate to 1 MOA. We easily see a 30 degree shift in temperature over the course of an average day. 65 in the morning and 95 in the late afternoon... so we see it a lot.
It's why you use a log book to follow the "trends" and why we don't sweat the small differences, and simple believe the bullet. It will tell you what it wants and its best not to argue with it. But how your rifle, ammo, and shooting trends is usually unique to each shooter and rifle.
As I have stated over and over, with most things being equal, we see as much as 2 Mils in variation between a group of shooters using the same rifle system and same ammo, for wind alone at 1000 yards... we saw it last week with everyone using the same, newly barreled rifles, Federal Ammo and NF scopes, yet most shooters use different dope to hit the same target. Different elevation and different wind... each shooter is unique, each rifle delivers the bullet in a different way. A barrel cut with a new tool will be different than a barrel cut with a tool that is nearing the end of its life, the twist rate will change slightly for each barrel. So science is great for an average but none of this accounts for the variation in shooters. Its why we see a right hand shooter hold 3 Mils of wind and a left hand shooter hold 1.5 Mils to hit the same target at the same distance at roughly the same time.
You can wrap your head around the little things so much you short circuit or you can focus on your shooting... its the guys that don't get caught up in the bullshit "rules of thumb" that tend to succeed. They follow the trends and understand when it some times deviates to simply correct for the next shot and move on.
We also see a lot of rifles that during the course of a week require a heck of lot of re-zeroing, not all, but many. Many of these errors are not picked up because people only shoot so much in a normal month. I recently asked one LE officer who saw his zeroing constantly shifting how long it would have taken for him during his normal training to fire as many rounds has he did, and the answer was 9 months. So a shift over 9 months can be attributed to many things, poor equipment would not be one of them, yet here you are in a one week class chasing your zero after every 100 to 200 rounds.
Absolutely your dope changes from day to day... we see it everyday in every class.
Your DOPE is just that... Data On Previous Engagement and doesn't mean what you shot last week will be exactly the same as this weekend, especially if you track it very closely. With a steel plate like a Larue, which is 12X22 at 650 yards that is quite a bit of elevation you can hide within the target, 3.3 MOA worth of difference. If you shoot paper you can track it better, but that still may change. Temperature, Barometric pressure will change it a bit, but that doesn't always translate to 1 MOA. We easily see a 30 degree shift in temperature over the course of an average day. 65 in the morning and 95 in the late afternoon... so we see it a lot.
It's why you use a log book to follow the "trends" and why we don't sweat the small differences, and simple believe the bullet. It will tell you what it wants and its best not to argue with it. But how your rifle, ammo, and shooting trends is usually unique to each shooter and rifle.
As I have stated over and over, with most things being equal, we see as much as 2 Mils in variation between a group of shooters using the same rifle system and same ammo, for wind alone at 1000 yards... we saw it last week with everyone using the same, newly barreled rifles, Federal Ammo and NF scopes, yet most shooters use different dope to hit the same target. Different elevation and different wind... each shooter is unique, each rifle delivers the bullet in a different way. A barrel cut with a new tool will be different than a barrel cut with a tool that is nearing the end of its life, the twist rate will change slightly for each barrel. So science is great for an average but none of this accounts for the variation in shooters. Its why we see a right hand shooter hold 3 Mils of wind and a left hand shooter hold 1.5 Mils to hit the same target at the same distance at roughly the same time.
You can wrap your head around the little things so much you short circuit or you can focus on your shooting... its the guys that don't get caught up in the bullshit "rules of thumb" that tend to succeed. They follow the trends and understand when it some times deviates to simply correct for the next shot and move on.
We also see a lot of rifles that during the course of a week require a heck of lot of re-zeroing, not all, but many. Many of these errors are not picked up because people only shoot so much in a normal month. I recently asked one LE officer who saw his zeroing constantly shifting how long it would have taken for him during his normal training to fire as many rounds has he did, and the answer was 9 months. So a shift over 9 months can be attributed to many things, poor equipment would not be one of them, yet here you are in a one week class chasing your zero after every 100 to 200 rounds.
Re: Can windage affect elevations adjustment?
This link explains why ballistic programs may be wrong, but it also explains why your dope may change from day to day. Not many people know how much their muzzle velocity changes with temperature variations.
Sources of Ballistic Program Inaccuracies
This link explains why ballistic programs may be wrong, but it also explains why your dope may change from day to day. Not many people know how much their muzzle velocity changes with temperature variations.
Sources of Ballistic Program Inaccuracies
Re: Can windage affect elevations adjustment?
i agree with Frank on this one. i just shot a comp in pissing ran the 2 days before we shot the range then again but this time it was earlier int he morning and colder it also started realy pissing with rain i could barley see the target i thought because of the extra weather i would come up a moa not a good idea hit a moa high came back to my 900 zero and straight into the X then again at 1000 yards this time just ran with the previous zero when it was 40 degrees hotter and dry straight into the guts.
it would apper to me to be positional or scope related 2 moa at such a close range it not right is the paralax set correctly if the scope is OK this could have been causing it because of the reticle mooving when your head position moves this would run true as you dialed the elevation and then refocused in a diferent position.
i would re check the paralax and then test the scopes tracking at a closer range loke 100 yards with a 6 foot square piece of paper as a target scopes have been known to be up the shit after one shot it does not meen because the scope is new there is not a porblem. Also set up the target and shoot with diferent head positions and body positions see if the diferent positions are having an effect on barrel pressures if you dont have a free floated barrel. some newer plastic stocks that have a small amount of clearence can contact the barrell under recoil or position changes giving a diferent POA.
i agree with Frank on this one. i just shot a comp in pissing ran the 2 days before we shot the range then again but this time it was earlier int he morning and colder it also started realy pissing with rain i could barley see the target i thought because of the extra weather i would come up a moa not a good idea hit a moa high came back to my 900 zero and straight into the X then again at 1000 yards this time just ran with the previous zero when it was 40 degrees hotter and dry straight into the guts.
it would apper to me to be positional or scope related 2 moa at such a close range it not right is the paralax set correctly if the scope is OK this could have been causing it because of the reticle mooving when your head position moves this would run true as you dialed the elevation and then refocused in a diferent position.
i would re check the paralax and then test the scopes tracking at a closer range loke 100 yards with a 6 foot square piece of paper as a target scopes have been known to be up the shit after one shot it does not meen because the scope is new there is not a porblem. Also set up the target and shoot with diferent head positions and body positions see if the diferent positions are having an effect on barrel pressures if you dont have a free floated barrel. some newer plastic stocks that have a small amount of clearence can contact the barrell under recoil or position changes giving a diferent POA.
Re: Can windage affect elevations adjustment?
Magnus Effect (a vertical component to wind drift, derived mainly from the cosequences of crosswinds combined with bullet rotational effects) is highly unlikely to have that sort of magnitude. The effect has the appearance of a very low amplitude sine wave, with the shape (whether the left or right half faces up) being dependent on the direction of rifling twist.
Horizontal adjustments can bind up vertical adjustments when both are near their limits, but this is also probably unlikely in this case.
Terrain, head/tailwinds, and operator inconsistencies (I refuse to call them errors because, very simply, none of us is ever perfect) in tandem are probably the more likely cause(s) of this observed effect.
Frank is also dead right on about zeroes varying day to day. I seldom alter either my competitive course/distance of fire, my handloads, or my sights; and they have never (NEVER!), ever been good to go unchanged the next time out.
Years ago this site had some articles about accuracy shooting, and one of the key concepts was 'the system'; a compilation of firearm, ammunition, shooter, and environment which performed in concert to deliver a coincidental POI/POA relationship. Very complex, and always in flux. The key to success involved eliminating equipment inconsistencies, developing consistent technique, and acquiring a familiarity with the visible manifestations of environmental conditions and how they impact upon accuracy. One may never get it all 'together'; but one can gain an incremental march on the quarry.
Greg
PS, Upon reflection; I note that I am just as prone to spouting "B*llsh*t" as the next guy...
Magnus Effect (a vertical component to wind drift, derived mainly from the cosequences of crosswinds combined with bullet rotational effects) is highly unlikely to have that sort of magnitude. The effect has the appearance of a very low amplitude sine wave, with the shape (whether the left or right half faces up) being dependent on the direction of rifling twist.
Horizontal adjustments can bind up vertical adjustments when both are near their limits, but this is also probably unlikely in this case.
Terrain, head/tailwinds, and operator inconsistencies (I refuse to call them errors because, very simply, none of us is ever perfect) in tandem are probably the more likely cause(s) of this observed effect.
Frank is also dead right on about zeroes varying day to day. I seldom alter either my competitive course/distance of fire, my handloads, or my sights; and they have never (NEVER!), ever been good to go unchanged the next time out.
Years ago this site had some articles about accuracy shooting, and one of the key concepts was 'the system'; a compilation of firearm, ammunition, shooter, and environment which performed in concert to deliver a coincidental POI/POA relationship. Very complex, and always in flux. The key to success involved eliminating equipment inconsistencies, developing consistent technique, and acquiring a familiarity with the visible manifestations of environmental conditions and how they impact upon accuracy. One may never get it all 'together'; but one can gain an incremental march on the quarry.
Greg
PS, Upon reflection; I note that I am just as prone to spouting "B*llsh*t" as the next guy...
Re: Can windage affect elevations adjustment?
so I guess the question remains: at what point do you begin to account for Magnus effect? I am shooting 175's at 650 for example, and am hitting within a few inches of vertical center on my 12" steel target in no wind (a condition I am still waiting to encounter). The wind suddenly goes to 15@ 3 everything else stays the same. how much of a vertical effect will there be? At what range and/or wind speed should you start to account for it? I know it will probably be enough to loose a bench rest match, but is it enough worry about shooting steel? thanks
so I guess the question remains: at what point do you begin to account for Magnus effect? I am shooting 175's at 650 for example, and am hitting within a few inches of vertical center on my 12" steel target in no wind (a condition I am still waiting to encounter). The wind suddenly goes to 15@ 3 everything else stays the same. how much of a vertical effect will there be? At what range and/or wind speed should you start to account for it? I know it will probably be enough to loose a bench rest match, but is it enough worry about shooting steel? thanks
Re: Can windage affect elevations adjustment?
I don't really have a reliable way of calculating vertical offsets due to Magnus. I simply try a few shots without any holdoff during sighter period and then apply hold-offs (and -over/unders) on a Kentucky windage basis. Trends appear, and one takes them into acount. I know this isn't a precise answer, but I really believe a lot of this gets eaten up by background 'noise'.
I concur, bad for benchrest, maybe not so significant an issue with steel.
I don't really have a reliable way of calculating vertical offsets due to Magnus. I simply try a few shots without any holdoff during sighter period and then apply hold-offs (and -over/unders) on a Kentucky windage basis. Trends appear, and one takes them into acount. I know this isn't a precise answer, but I really believe a lot of this gets eaten up by background 'noise'.
I concur, bad for benchrest, maybe not so significant an issue with steel.
Re: Can windage affect elevations adjustment?
In most any shooting scenario time is not on your side. Since wind will always have the most effect on external ballistics that's the only thing, in addition to distance to target, for certain, I'll address on the spot. If, or how I account for temperature/humidity, slope, and/or light is dependent on having the time and/or the knowledge of the change in condition effect on the bullet.
A data or score book will come to your aid when changing conditions as seen before appear to you again. This may be when a rule of thumb, like "lights up sights up" could be useful, if indeed your score book suggests that to not make the correction would produce a group somewhat lower than desired on the target.
Think about it like this, if you've got something as big as an E target appearing to you at a known distance, or one you can range accurately, will a good hit require any more than a good wind favor? Unless the target is way out there, slope and temperature may not need consideration.
Also, for something like NRA LR, unlimited sighting shots usually precludes any thinking beyond concentration on the firing task and wind changes.
The point here is that you don't need to be a watchmaker to tell time. And, why expend the energy to be accurate to the second when only being accurate to the quarter hour is necessary? Circumstance will dictate when ballistics knowledge beyond the basic drag and gravity concepts will be useful.
Sure, the more you know about external ballistics the better your shooting will likely be, but with enough practice most of this stuff becomes intuitive, or can be taken into account before coming to the firing line. leaving only wind to think about. Most of the time wind will keep you as busy as you're prepared to be.
In most any shooting scenario time is not on your side. Since wind will always have the most effect on external ballistics that's the only thing, in addition to distance to target, for certain, I'll address on the spot. If, or how I account for temperature/humidity, slope, and/or light is dependent on having the time and/or the knowledge of the change in condition effect on the bullet.
A data or score book will come to your aid when changing conditions as seen before appear to you again. This may be when a rule of thumb, like "lights up sights up" could be useful, if indeed your score book suggests that to not make the correction would produce a group somewhat lower than desired on the target.
Think about it like this, if you've got something as big as an E target appearing to you at a known distance, or one you can range accurately, will a good hit require any more than a good wind favor? Unless the target is way out there, slope and temperature may not need consideration.
Also, for something like NRA LR, unlimited sighting shots usually precludes any thinking beyond concentration on the firing task and wind changes.
The point here is that you don't need to be a watchmaker to tell time. And, why expend the energy to be accurate to the second when only being accurate to the quarter hour is necessary? Circumstance will dictate when ballistics knowledge beyond the basic drag and gravity concepts will be useful.
Sure, the more you know about external ballistics the better your shooting will likely be, but with enough practice most of this stuff becomes intuitive, or can be taken into account before coming to the firing line. leaving only wind to think about. Most of the time wind will keep you as busy as you're prepared to be.
Re: Can windage affect elevations adjustment?
Range, Wind, Fundamentals is the mantra...
E Type ? who the heck is shooting those..
Range, Wind, Fundamentals is the mantra...
E Type ? who the heck is shooting those..
Re: Can windage affect elevations adjustment?
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"> The point here is that you don't need to be a watchmaker to tell time. And, why expend the energy to be accurate to the second when only being accurate to the quarter hour is necessary? Circumstance will dictate when ballistics knowledge beyond the basic drag and gravity concepts will be useful.
</div></div>
Succinct, astute, wish I'd said this...
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"> The point here is that you don't need to be a watchmaker to tell time. And, why expend the energy to be accurate to the second when only being accurate to the quarter hour is necessary? Circumstance will dictate when ballistics knowledge beyond the basic drag and gravity concepts will be useful.
</div></div>
Succinct, astute, wish I'd said this...
Re: Can windage affect elevations adjustment?
No matter how accurate your calculation of the factors affecting internal and external ballistics, it will likely avail you nought if you slap the trigger.
No matter how accurate your calculation of the factors affecting internal and external ballistics, it will likely avail you nought if you slap the trigger.
Re: Can windage affect elevations adjustment?
LL, I agree with your assessment of the most likely causes of this shooter's POI shift. That said, viewing the question of "does wind affect elevation POI" as a stand-alone subject, it is helpful to know this answer as well. Not to mention yet a third concept, that being the wind does not always blow in a level fashion regarding its affect on the projectile.
LL, I agree with your assessment of the most likely causes of this shooter's POI shift. That said, viewing the question of "does wind affect elevation POI" as a stand-alone subject, it is helpful to know this answer as well. Not to mention yet a third concept, that being the wind does not always blow in a level fashion regarding its affect on the projectile.
Re: Can windage affect elevations adjustment?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">
E Type ? who the heck is shooting those..
</div></div>
Of course you're not serious?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">
E Type ? who the heck is shooting those..
Of course you're not serious?
Re: Can windage affect elevations adjustment?
Lowlight and Lindy,
Sage advice and much thanks for it.
RB
Lowlight and Lindy,
Sage advice and much thanks for it.
RB
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