Today while shooting, my poi was consistently high, usually a moa or higher from 200-600 m. Not much a temperature change from my last outing and shooting at the same range. There was a drastic difference ar 500 and 600. I checked a ballistics progarm whem I got home and it confirmed my dope should have been the same. Obviously its me because there should not be that much a change, I don't think so anyway. Can anyone explain this, I have been shooting a long time and this is the first time this has happened.
Advanced Marksmanship POI high, temperature?
- Thread starter Vin
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Re: POI high, temperature?
You should list your rifle and scope specs as well as what ammo, etc... the more detail the better for people to help diagnose the issue, if there is indeed one.
You should list your rifle and scope specs as well as what ammo, etc... the more detail the better for people to help diagnose the issue, if there is indeed one.
Re: POI high, temperature?
Density altitude could have risen sharply.....
No location on your profile, so I can't correlate with any weather sites, but you could.
Density altitude could have risen sharply.....
No location on your profile, so I can't correlate with any weather sites, but you could.
Re: POI high, temperature?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: sobrbiker883</div><div class="ubbcode-body">Density altitude could have risen sharply.....</div></div>
DA could explain being off at longer distances .... but not at 200.
For a 5K' DA change, you're talking about .4 Mils difference at 600. He's off by almost that much at 200!
I'd start by confirming your zero, checking your mounts are secure, and running a box test on the scope.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: sobrbiker883</div><div class="ubbcode-body">Density altitude could have risen sharply.....</div></div>
DA could explain being off at longer distances .... but not at 200.
For a 5K' DA change, you're talking about .4 Mils difference at 600. He's off by almost that much at 200!
I'd start by confirming your zero, checking your mounts are secure, and running a box test on the scope.
Re: POI high, temperature?
A 20 degree temp change or heavy change in BP, humidity, etc could do it. Or did you leave your rounds in the sun for too long?
A 20 degree temp change or heavy change in BP, humidity, etc could do it. Or did you leave your rounds in the sun for too long?
Re: POI high, temperature?
the 20 degree thing isn't true and really never was as they never told you where that 1 MOA would change and it certainly doesn't change 1 MOA at 200 like has been stated. And humidity barely has a .25MOA effect at 1000 yards let alone anywhere else inside that distance.
It's 2009, we have better powders that are less temperature sensitive since they made that 20 degree rule of thumb back 40 years ago. Most of today's modern bullets are far less sensitive until you get past 600.
I would follow some of the other advice, check your zero, check your scope, etc... unfortunately not all rifles are created equal and some are just not as good as we expect them to be, so really anything could be off. Time to start eliminating variables because I don't think it was the temperature.
the 20 degree thing isn't true and really never was as they never told you where that 1 MOA would change and it certainly doesn't change 1 MOA at 200 like has been stated. And humidity barely has a .25MOA effect at 1000 yards let alone anywhere else inside that distance.
It's 2009, we have better powders that are less temperature sensitive since they made that 20 degree rule of thumb back 40 years ago. Most of today's modern bullets are far less sensitive until you get past 600.
I would follow some of the other advice, check your zero, check your scope, etc... unfortunately not all rifles are created equal and some are just not as good as we expect them to be, so really anything could be off. Time to start eliminating variables because I don't think it was the temperature.
Re: POI high, temperature?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rijndael</div><div class="ubbcode-body">
DA could explain being off at longer distances .... but not at 200.
For a 5K' DA change, you're talking about .4 Mils difference at 600. He's off by almost that much at 200!
I'd start by confirming your zero, checking your mounts are secure, and running a box test on the scope. </div></div>
You're absolutely right, I was thinking of the couple/few moa changes I've seen with 168's with a 4K change, but that was at 800+yds.......
Trying to diagnose vague elevation changes online is going to be an excercise in futility.
Make sure everything's tight, rezero and reshoot-then compare what you get to actual data from prior shooting. Programs can be close, but rarely 100%.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rijndael</div><div class="ubbcode-body">
DA could explain being off at longer distances .... but not at 200.
For a 5K' DA change, you're talking about .4 Mils difference at 600. He's off by almost that much at 200!
I'd start by confirming your zero, checking your mounts are secure, and running a box test on the scope. </div></div>
You're absolutely right, I was thinking of the couple/few moa changes I've seen with 168's with a 4K change, but that was at 800+yds.......
Trying to diagnose vague elevation changes online is going to be an excercise in futility.
Make sure everything's tight, rezero and reshoot-then compare what you get to actual data from prior shooting. Programs can be close, but rarely 100%.
Re: POI high, temperature?
from your last outing to this most recent , did you do anything to your rifle , that makes it different than it was ?
like, add a cheekpiece or padding, raise or lower your cheekpiece, shoot from a different position (off a bench , now this time off the ground ) , change recoil styles (free recoil , now you are pulling the gun in tightly ?)
add a bipod, or experience bipod issue that made you fight the torque , did the bipod dig into the ground ?
change optics, ?
also body position angle change will cause a POI change as well
tough to call , as you don't list weapon/optics/ load information , factory or handloads etc.,
but you are right chances are its you
from your last outing to this most recent , did you do anything to your rifle , that makes it different than it was ?
like, add a cheekpiece or padding, raise or lower your cheekpiece, shoot from a different position (off a bench , now this time off the ground ) , change recoil styles (free recoil , now you are pulling the gun in tightly ?)
add a bipod, or experience bipod issue that made you fight the torque , did the bipod dig into the ground ?
change optics, ?
also body position angle change will cause a POI change as well
tough to call , as you don't list weapon/optics/ load information , factory or handloads etc.,
but you are right chances are its you
Re: POI high, temperature?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: banshee sws</div><div class="ubbcode-body">tough to call , as you don't list weapon/optics/ load information , factory or handloads etc.,</div></div>
He did, in the 3rd post.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Vin</div><div class="ubbcode-body">The rifle is a Rem 700 Custom,w/ a Rock 22" M24 countour barrel with a mv of 2665 fps. Scope is a NF NXS 3.5-15 x 50 w/ NP R1 moa reticle and ammo is Federal GMM 168 gr.</div></div>
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: banshee sws</div><div class="ubbcode-body">tough to call , as you don't list weapon/optics/ load information , factory or handloads etc.,</div></div>
He did, in the 3rd post.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Vin</div><div class="ubbcode-body">The rifle is a Rem 700 Custom,w/ a Rock 22" M24 countour barrel with a mv of 2665 fps. Scope is a NF NXS 3.5-15 x 50 w/ NP R1 moa reticle and ammo is Federal GMM 168 gr.</div></div>
Re: POI high, temperature?
Thanks for the info guys, I know its hard to diagnose over a computer. The ammo was the same lot, barrel clean, scope or action was not removed. I am going again tomorrow and see what happens. I would suspect its me but you never know, I thought I would ask as there is alot of knowledge here.
Thanks for the info guys, I know its hard to diagnose over a computer. The ammo was the same lot, barrel clean, scope or action was not removed. I am going again tomorrow and see what happens. I would suspect its me but you never know, I thought I would ask as there is alot of knowledge here.
Re: POI high, temperature?
There's nothing here I can point to and say, "Yep; Dassit!".
What I conjecture will happen is that the rifle could even shoot to another, third, POI.
I think there's a human factor in the dynamics of this system that is inconsistent. This is not a critism, but rather a possible confirmation of the idea that shooting basics make a difference, often <span style="font-style: italic">the</span> difference, between the results of one string and those of another.
Greg
There's nothing here I can point to and say, "Yep; Dassit!".
What I conjecture will happen is that the rifle could even shoot to another, third, POI.
I think there's a human factor in the dynamics of this system that is inconsistent. This is not a critism, but rather a possible confirmation of the idea that shooting basics make a difference, often <span style="font-style: italic">the</span> difference, between the results of one string and those of another.
Greg
Re: POI high, temperature?
I had a similar problem about 1 hr ago.
Will you get that much POI change with a long string that makes the barrel hot?
My change was about .4 - .5 mil @ 500 yds. Equipment is roughly the same as Vin, 20" GAP w/S&B on top.
Environmental changes seem to small for the effect I had.
I had a similar problem about 1 hr ago.
Will you get that much POI change with a long string that makes the barrel hot?
My change was about .4 - .5 mil @ 500 yds. Equipment is roughly the same as Vin, 20" GAP w/S&B on top.
Environmental changes seem to small for the effect I had.
Re: POI high, temperature?
I did this video today, sort of off the cuff based on a question asked yesterday in the online training section.
So, here you go:
<object width="425" height="350"> <param name="movie" value="http://www.youtube.com/v/3UZ-mApuUoM"></param> <param name="wmode" value="transparent"></param> <embed src="http://www.youtube.com/v/3UZ-mApuUoM" type="application/x-shockwave-flash" wmode="transparent" width="425" height="350"> </embed></object>
Basically, went to the range this morning, 81 degrees when we arrived. I zeroed the rifle, and placed it and the ammo in the sun on the tailgate of the truck. Kestrel readings taken showed the bed of the truck read 100 degrees. After I went back and zeroed a completely different rifle, about a half hour later, I shot 20 rounds on a steel target at 550 yards. Then I took a single round and shot a dot target at 100 yards to see if I had a shift like some were experiencing, so the results are listed.
Another related video is the point of impact change from position which I will post in its proper place.
it's now where near scientific, and it was designed to address 100 yards, but the rounds did not walk up at 550 either. In the future it could expanded to paper at distance to shot more of the effects at long range, but that wasn't the question... any way, small demonstration if nothing else.
I did this video today, sort of off the cuff based on a question asked yesterday in the online training section.
So, here you go:
<object width="425" height="350"> <param name="movie" value="http://www.youtube.com/v/3UZ-mApuUoM"></param> <param name="wmode" value="transparent"></param> <embed src="http://www.youtube.com/v/3UZ-mApuUoM" type="application/x-shockwave-flash" wmode="transparent" width="425" height="350"> </embed></object>
Basically, went to the range this morning, 81 degrees when we arrived. I zeroed the rifle, and placed it and the ammo in the sun on the tailgate of the truck. Kestrel readings taken showed the bed of the truck read 100 degrees. After I went back and zeroed a completely different rifle, about a half hour later, I shot 20 rounds on a steel target at 550 yards. Then I took a single round and shot a dot target at 100 yards to see if I had a shift like some were experiencing, so the results are listed.
Another related video is the point of impact change from position which I will post in its proper place.
it's now where near scientific, and it was designed to address 100 yards, but the rounds did not walk up at 550 either. In the future it could expanded to paper at distance to shot more of the effects at long range, but that wasn't the question... any way, small demonstration if nothing else.
Re: POI high, temperature?
All,
There are a multitude of problems/errors which could get the result described here; and, temperture certainly could be a factor. For sure, something, or some things about the gun, shooter, and/or the ammunition are not consistent- who knows, but, since all firing takes place at the firearm, ultimately, the shooter will need to resolve it all.
Proper trouble-shooting (shooter/target analysis) can get the correct answer, very quickly. The analysis is easier when shots are recorded in a data book.
All,
There are a multitude of problems/errors which could get the result described here; and, temperture certainly could be a factor. For sure, something, or some things about the gun, shooter, and/or the ammunition are not consistent- who knows, but, since all firing takes place at the firearm, ultimately, the shooter will need to resolve it all.
Proper trouble-shooting (shooter/target analysis) can get the correct answer, very quickly. The analysis is easier when shots are recorded in a data book.
