problem 338 Lapua, gun or scope

[Thekid76]

hay guys, I have to get some more feedback on this one since I am running out of thoughts,
I just completed the build on a 338 Lapua with a Gary Schneider P5 1 in 9 twist MTU, on a CZ 550 action, bedded into a CZ HET kevlar stock with full length rail. I have glassed the action and had Talley mounts installed for 30mm optics. At this time I have to reserve the right to not mention the optics due to them helping me out on this, but I have to spill my guts on the results with this rifle, as I need some confirmation that this is most likely not the rifle, but the optic. I also have a JP brake on it. Now what I am looking for, just to remain sane, is confirmation that this problem is most likely not being caused by the brake, or chamber run out, or crown, or bedding, or bad barrel, but I would like you all to be honest.

Day one: 2 out of 5 groups go under MOA, but just barely. I am shooting 300smk with R25 and H1000. the loadings started just .015 off the lands with standered loading practices.

Day two: Still trying to tune 300 and now 265 match bullets, first grouping is 4.5 inches at 100, second string is 3. I let the gun cool and check my loads for run out again. check everything, Do not have a Chronograph so I say some bad words, but know that the loads are within .1gr of what I intend. scratching my head I go home to load up and try to tune bullet length one more step back. Todays loads were backed out .02, .025, and .03.

Day three: Have loaded up R22, IMR 4831, and 7828 just to see if I have a picky barrel. Loads are again set up to lands with the 300 smk and to .04 with the 265s, I also prep some h1000 with 300smk's so they are hard into the lands. I get the same results. 3 to 4 inch groups at 100 with only one group under 1 moa. This group was shot with h1000 and 300smk's hard into the lands.

I do not know what to think. I have started by checking the gun and it looks right in every respect. even if the bedding was bad or the action was just a hair out or whatever I should still be getting sub groups with this barrel and bullet? shouldn't I?

I have a Schneider barrel on an old military mauser action and the darn thing shoots to .3 without me even trying! I did not true the action or anything, just barrel and bang and the dang thing shoots awasome.

HELP++++
Marc

 

[BountyHunter]

Couple things come to mind right off the bat as the gun seems to be "inconsistent" when you look at the 1" groups.

1. Scope- try another scope that you know is proven. That will settle the scope issue.

2. Bedding- You need to have someone check the bedding with a dial indicator and see if it moves when the action screws are loosened. You cannot tell by looking normally and only the dial indicator will tell you if you have a problem. You might not have tension free bedding and that is causing the issue.

3. Have you checked the loaded rounds for runout and consistent COAL once loaded?

BH

 

[4xforfun]

I agree compleatly with Bountyhunters first fix........try another scope.

But on points 2 and 3....I can't imagin a bedding problem bad enough to give you 3 - 4- MOA groups......no way. Same for runout on loaded rounds. I loaded for a guy who had a 7mm-300 wby bench rifle. You could actualy see how crooked the bullet was when I used his dies. I rolled one across the counter and laughed out loud. I didn't check to see if it was his seater die or the FL die....it was just plain BAD!!! Anyway, I used my own dies, straitend out the problem with some new brass, and the gun did not shoot any better. Well, mayby a tiny bit, but only noticeable with my measuring tools. Around 1 inch...not good at all.

LOOK AT THE SCOPE!!!!!

If that don't fix it, get a bore scope and take a look.

 

[cedarswamp1]

I would pick a load and stick with it until you're able to find some consistency, IMHO you're introducing too many variables at once.


Assuming a proper barrel break-in, I too would switch to a scope I trusted, and one I trusted to handle the recoil of a 338 Lapua.

 

[trueblue]

Change scopes, and start with the 300grners .0020 off the lands.

 

[sniperjwt]

Couple things come to mind right off the bat as the gun seems to be "inconsistent" when you look at the 1" groups.

1. Scope- try another scope that you know is proven. That will settle the scope issue.

2. Bedding- You need to have someone check the bedding with a dial indicator and see if it moves when the action screws are loosened. You cannot tell by looking normally and only the dial indicator will tell you if you have a problem. You might not have tension free bedding and that is causing the issue.

3. Have you checked the loaded rounds for runout and consistent COAL once loaded?

BH

+1 to the above i think this is the first case i have heard of a 338 lapua shooting badly

 

[Thekid76]

man, you guys are on the ball, Thank you for the fast replies. I took the scope off and stuck it on a 280 i had forgotten about in the back of my safe. the gun had a card with it that had load data and a .5 inch group. it is a rem mountain rifle from another time in my life, any way it had some 30 mm rings, so I put the scope on this rifle and headed out with the loaded ammo that shot the .5. bingo. after fowling the barrel I tracked the scope to 0 and shot 100yard target. first round on the money but .5 low.. the next ten shots strung out to the right and off the target. for some reason this was not as pronounced on the Lapua. the 280 kicks very sharp due to the 6.5 lbs and the scope did not show this bad tracking on the heavy gun but then its recoil is straight back and lighter than a 264 win so again I think we found the problem.

thanks and keep writing great stuff.
marc

 

[sniperjwt]

glad to hear it was something simple