Range Report barrel settling in?

[merrjm]

i'm shooting a fairly new savage f t/r .308.
i have gone from 12.5-12.75 moa at 600yds down to 11.0-11.25 moa in the last 2 matches i have shot. the first i attributed to air temp(85-90f) and out in the sun. i did keep the ammo box covered at all times. the second match roughly the same temp. and shooting from the shade with ammo covered.
i have changed nothing in the load and have shot in the heat before. i now have about 900 rounds down the tube. is the barrel finally setteling in or is the temp making the change?

load: 155 berger match vld
cci 200 primer
45.5 gr varget
c.o.a.l. 2.895"
any ideas??

 

[turbo54]

Re: barrel settling in?

1-1.5 moa is pretty big.

I choose option C: none of the above.

What scope?

 

[merrjm]

Re: barrel settling in?

sightron 3 8-32. i also thought 1-1.5 was quite a bit. the scope was recently put on(before the last 2 matches) but the original dope from jbm calls for 12.5 @600 that is what i've been shooting for better than a year now. may be scope, i dunno

 

[Pusher591]

Re: barrel settling in?

Varget is pretty temp stable from what I understand. The more I shot my Brux the faster it got until about 500 rds, then it just leveled off.

I'm sure it's just getting good and broken in

 

[BK7saum]

Re: barrel settling in?

Id check your scope. Turret calibration might be off. If you changed 1.5 moa in one step and not gradually I doubt it is settling in especially since the change coincided with a scope change.

Shoot at 100, dial up, and shoot again to verify your turret function

 

[427Cobra]

Re: barrel settling in?

I have noticed my barrels get faster between 300-700 rounds, some more than others.

 

[Greg Langelius *]

Re: barrel settling in?

Same height rings?

 

[9H_Cracka]

Re: barrel settling in?

A new Krieger I screwed on 5 days before shooting in the national matches at Camp Perry this year moved a bunch. I had 122 rounds on it when I left - thought it would have been stable.

Wind zero moved 2 minutes left before week's end, in 2 big moves - 1 1/4 minutes in one day of 82 shots, then 3/4 minutes in the next day of 58 shots.

Elevation zero moved down 1 1/4 minutes too at 600.

Total round count is at 530 now and it was stable the last 3 days (66 shots/day).

Still, 1.5 MOA is a bunch. I suspect a combination of barrel settling, atmospheric differences, and you controlling the muzzle better as your time with the rifle increases.

 

[223ai]

Re: barrel settling in?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: _9H_Cracka</div><div class="ubbcode-body"> I suspect a combination of barrel settling, atmospheric differences, and you controlling the muzzle better as your time with the rifle increases.</div></div>

I'd be willing to bet that this is the correct diagnosis, especially the "controlling the muzzle" comment. You're probably just driving the rifle that much butter.

 

[ChadTRG42]

Re: barrel settling in?

Correct with what was said above. Heat will play a lot with ammo temps and speeds, even with your extreme powder, like Varget. The extreme powders help minimize the effect of outside temps, but they don't eleminate it. And yes, barrels will pick up some speed after the first 150 to 300 rounds. My 260 Rem did this and picked up 120 fps after 150 rounds. So, it could be a combination of all 3. And I have also seen POI shifts from a 70 degree morning to 95-100 degree day in the afternoon. I would be hitting 1 to 1.5 moa high at 100 yards in the afternoon, when zero'd at 100 that morning. So, things do move around sometimes.

 

[merrjm]

Re: barrel settling in?

greg,
yes the same rings as before. i have been bangin my head against the wall trying to figure this out. i have come to the conclusion that "it is what it is ",along with some of the other reasons posted.
i will try some things next time i go to the range. 100yd zero, turet calib and m.v.
thanks for all of the info

 

[9H_Cracka]

Re: barrel settling in?

If the POI marches up the paper in the same pattern from cold bore as you attempt to shoot a group, then you have stress in the barrel. Not good, in fact unacceptable in my book and it would get screwed off. If the zero moved cold and hot, my comments I think explain what is going on.

 

[9H_Cracka]

Re: barrel settling in?

Oh one more thing - as the barrel picks up its round count it generally picks up velocity, which also will change your come-ups at distance.

 

[merrjm]

Re: barrel settling in?

9H,
i'm not vertically stringing, in fact last match had damn near perfectly horizontal line about 6 inches wide.
really thinking about it even more, i ran the dope from jbm out to 850 and was pretty close to where i was before the optics change (within 1/4-1/2moa)before last 2 matches it was real close. i really dont know or understand how i can be lower at 600 and in the ball park at 850.
i may have bumped zero after shooting 850 before the 2 matches.
i've got some figuring to do in the next couple of weeks.
will post what i figure out.

thanks guys for all of your help and suggestions