338 Lapua Reloading Struggles

[benjaminallen1]

Hey Guys - really have never used the forum here before so please show some forgiveness if my post contains any ignorance.

Had a 338 Lapua put together by Elk Meadow Performance out of Utah about two years ago. It really just consists of a Christensen Summit Ti with the factory barrel spun off and replaced with a custom 22" Proof Research barrel built with a 1:8 twist and a titanium muzzle brake. I have the gun topped with a Zeiss Conquest V6. I haven't done a TON of reloading before but the reloading I have done for other guns has produced excellent results for me (1/4 - 1/2" MOA groups out of some of my other guns). For whatever reason, I can't seem to work up a load for the life of me with this gun though so I am hoping others may have some input on where I am going wrong.

For barrel break-in procedures, I used Nosler 225 gr. accubonds and Nosler 300 gr. accubonds and both produced ~2" groups at 100 yards.

After barrel break-in, I ordered up a set of custom whidden dies and started loading the following:

• Bullets: 300 gr. Berger Elite Hunter & 285 gr. Hornady ELD-M
• Primer: 215M
• Brass: Lapua
• Powders: H1000 & IMR 7977

I have messed with seating depth loading all the way up into the lands and then backing my bullet out all the way to thirty thousandths. Also ran powder charges from mins up to maxes going in .2 grain increments. I never really could hit a sweet spot with any combination I tried. Thus far, I am probably 350 rounds into load development and still have not found any combination that shoots better than ~1.5" groups, which for the setup I am running, simply has me wondering if there is something I am doing wrong or something I haven't thought of yet. Any thoughts, comments, or suggestions down this road of load development that may help in tightening up these groups or finding a load that can get me sub-moa would be greatly appreciated!

 

[tstith]

To eliminate all factors, what factory rounds have you tried? How did they perform? If there is a discrepancy between factory rounds vs your reloads, then you can keep banging your head against the wall trying to determine what is causing groups like that. I trust that you're experienced enough with your reloading and load development that I won't try to critique it past that. The bullets should be stabilized with that twist rate. You're using a well known, reputable primer. *Possibly* try another powder but I see no problems wit the ones you're using. If its shooting factory rounds and your reloads like that, try reaching out to Proof or Elk Meadow.

 

[wind gypsy]

I’m not sure this is the cause but you’re shooting bullets that are stabilized by a 10 twist through an 8 twist. I have seen/heard enough from gunsmiths and barrel makers that suggest over spinning can impact accuracy. It definitely impacts accuracy if the bullets aren’t up to the task.

What have you done to verify it isn’t the scope and scope mounting system? Have you spoken to the gunsmith about it?

 

[benjaminallen1]

Hey Gentlemen - Thank you for your initial input and my apologies for being late to respond. I am attorney for the government and as I am sure you can imagine, things have been fairly crazy for us the last two months.

The factory rounds I used were Nosler 225 gr. accubonds and Nosler 300 gr. accubonds. I have contemplated trying to get my hands on some N570 powder but it has been sold out everywhere for longer than I can remember. I guess I could try to Retumbo powder as I know some Lapua guys have luck with that.

The scope itself is the only scope I have run on it. Its a Zeiss Conquest V6. Initially I had Nightforce rings on it but I didn't have enough elevation travel so I switched over to the Burris XTR signature rings to gain some travel. As far as accuracy is considered though, neither made a difference.

The one thing I did identify between my original post and now is that my barrel technically had "some" contact with the stock. I did the old dollar bill test and identified that the dollar stopped about two inches short of my recoil lug. I removed the stock and took a Dremel to the stock, retorquing everything back to spec. I have not had a chance to go back out and shoot but with this change, I figured I might just start back over from square one with some ladders. If this doesn't solve it, I am a little at a loss for solutions unless you fellas have anything else you can think of that I haven't tried yet.

Thanks for all of the input!

 

[BAKPAKR]

If your recent stock work doesn’t improve your groups, it might be worthwhile to call Hammer Bullets or Cutting Edge Bullets to see what bullets they would recommend for an 8 twist 338. Both companies offer long, heavy mono bullets that require fast twists.

Your rifle sounds pretty light. What does it weigh? I imagine the muzzle blast is pretty significant from a short, braked barrel. I would probably have some mental stuff going on shooting a loud, lightweight 338. Have you let anyone who is comfortable shooting big guns shoot it?

I have had good luck with Retumbo in my 27” 1:10 twist 338 LM with 250 gr Hornadys and 300 gr Bergers. It worked better than H1000 for me.

 

[benjaminallen1]

Bakpakr - thank you for the input. Yes the gun is very light. We actually have four of the Christensen Summit Ti's in our group - the other three have been left stock, this is the only one that has been customized as I wanted the shorter barrel with the tighter twist rate so mine has had all of the modifications and as such, doesn't shoot as well as the others. However, as far as weight is concerned, they all weigh about the same.