Rifle shooting high

[jaym_100]

I get to the range at 1415hours and shoot a cold bore and 2 other shots dead on with winchester match ammo. The sun is high in the sky and I'm under an awning. I shoot several more groups at 100 yards all are under 1 moa most 1/2 moa or less. I shoot at 200, 250 and 350 then back to 100. My next 100 yard shot is about 3/4 to 1 inch high. I then change to my hunting ammo that was shooting a little low. (165gr SMK) I shoot 100 dead on. I then shoot 200, 250 and 350. By now its about 1645 hours and the sun is directly behind me. I shoot 100yds with winchester match and it is shooting .5 mils high. I 3 groups of 3 all are smaller than a penny and .5 mils high. I dial .5 mils low and hit dead on. Then proceed to move my turret between 1.5 mils to zero all hitting dead on. Does anyone know why my gun started shooting so high.

My set up
Remington 700 action
Krieger MTU 20 inch barrel
XLR Industries Stock
SWFA 5-20x50 Illuminated Reticle Scope
TPS Steel 20 moa base
TPS rings

 

[Sterling Shooter]

Re: Rifle shooting high

Here are some things that can be the source/s of your error: Temperature (a 20 degree change in temperature can be worth about 50 fps, or about 1 MOA), inconsistent butt-to-shoulder, inconsistent stock-weld, low gun position (changes perspective of aim, or parallax), inconsistent left elbow placement.

 

[timelinex]

Re: Rifle shooting high

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sterling Shooter</div><div class="ubbcode-body">Here are some things that can be the source/s of your error: Temperature (a 20 degree change in temperature can be worth about 50 fps, or about 1 MOA), inconsistent butt-to-shoulder, inconsistent stock-weld, low gun position (changes perspective of aim, or parallax), inconsistent left elbow placement. </div></div>
I thought at 100 yards temperature made much less of a difference. When I do a 60 degree temperature difference into my ballistics calculator I only get a 1/4MOA change... Unless you mean temperature of the ammo from the sun heating it up, but even then I thought most newer powders used are relatively temperature stable.

On the other hand the only other thing I can think of is tracking on the scope might be bad.

But there's a reason most of Sterling Shooters reasons were based around form.. Speaking from personal experiences, form what I can tell, a floating zero has always been because of bad form for me.

 

[Sterling Shooter]

Re: Rifle shooting high

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: timelinex</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sterling Shooter</div><div class="ubbcode-body">Here are some things that can be the source/s of your error: Temperature (a 20 degree change in temperature can be worth about 50 fps, or about 1 MOA), inconsistent butt-to-shoulder, inconsistent stock-weld, low gun position (changes perspective of aim, or parallax), inconsistent left elbow placement. </div></div>
I thought at 100 yards temperature made much less of a difference. When I do a 60 degree temperature difference into my ballistics calculator I only get a 1/4MOA change... Unless you mean temperature of the ammo from the sun heating it up, but even then I thought most newer powders used are relatively temperature stable.

On the other hand the only other thing I can think of is tracking on the scope might be bad.

But there's a reason most of Sterling Shooters reasons were based around form.. Speaking from personal experiences, form what I can tell, a floating zero has always been because of bad form for me.</div></div>

I too doubt it's got anything do do with ambient temperature, it's why I qualified my statement with the word "can". Shooter/target analysis always begins with a listing of what can cause shooter/target error. My post simply listed the things known to produce the results as described. When the error is consistent, you look for what has changed in the shooter's relationship with the gun and ground, or the gun itself, like a barrel which has warped. I don't know about a warped barrel here but a barrel which gets progressively hotter can certainly produce the sort of result the OP is describing. I've got a mountain of LR score books which indicate beginning and ending no wind zeros where it appears I progressively dropped clicks in elevation, as well as taken some windage too.

 

[jaym_100]

Re: Rifle shooting high

It can't be temperature change. I waited about thirty minutes for the barrel to cool down to see if it made a difference and it didn't. I thought about form changing but it wasn't one or two groups spread out. These were all very small groups all in the same spot with only vertical change. The scope tracked fine when I checked it, but the zero changed. I'm going to be pissed if my scope is broken. Hope to hit the range again wednesday.

 

[jaym_100]

Re: Rifle shooting high

My front action screw was loose. I think that is what was causing it to shoot high. It wasn't loose really but it wasn't at 65 pounds like the other one and it was when I put the stock on it. Will shoot again tomorrow and hopefully that was the problem.

 

[Hogstooth]

Re: Rifle shooting high

If that is a aluminum stock and it keeps coming loose I would try bedding it to fix that problem, or contact the mfg and see if they recommend lock tight or have them check the stock?

 

[TConfo]

Re: Rifle shooting high

For my first post, granted I'm a newbie, I would like to offer some possibilities. If its not temp change,wind etc( environmental factors). I'm guessing equiptment or user error. Inconsistent cheek weld, tracking on your scope may be off, maybe a screw lossened up on your mount or rings, or the bedding issue that was mentioned above. My advise is to take everything down, rescure it, and start tracking your scope paying attention to cheek weld and proper placement. A sled will help you rule some things out. Also, are you hand loading?

 

[Deleted member 10043]

Re: Rifle shooting high

You were shooting low to begin with. Reset your zero based on your high groups. Keep shooting until you find a comfortable zero setting based on your own shooting, equipment, and ammo. Believe your bullet first. Keep it simple.