Accuracy issues with a custom 338 Laupa

[kdumph]

Got my first long range hunting rifle from Snowy Mountain Rifles a few months ago and simply can't get her to group like I know she should. Have about 100 rounds down the barrel now.

Rifle info
1:10 Twist 28" Remington Varmint Contour Barrel
SMR 416 muzzle break
NXS 5.5-22
Manners MCS-TA
TS-100 SS Series in 338 Lapua.

Hand Load Info.
300gr Sierra Matchkings
89Gr(2700fps) & 93GR (2800fps) loads of Retumbo
Tried 4 different lengths from 3.950 up to 3.979
Laupa brass
Rem 9 1/2 Mag primers

300gr Berger Hybrid OTMs
93gr Retumbo (2800fps)
Tried 3 different lengths, kissing the lands, slightly off the lands, and magazine length.
Laupa brass
Rem 9 1/2 Mag primers

Have done a ladder test at 200 yards that didn't work very well, but my max load with a heavy bolt lift is 94gr with the the SMKs.

Even with all the variations I have tried the rifle shoots extremely consistently, just not very good groups. Best group I think I have had at 200 yards is about 1 1/2".

I'm kinda at a loss now to get these groups tighter. I have been following this guide pretty closely for the loading technique. Hand Loading for Long Range 1: Brass Prep

Perhaps another powder, bullet? With the fired brass length I am still about .20 off of what my max headspace measurement is. My last 2 reloads I have just selected my shortest round and trimmed to its length for consistency. Perhaps I should just not trim until I get up to that max length?

Forgot to add that on my second reloads on this new Lapua brass the case is slightly stiff when chambered even though I knocked the neck back.

Id be extremely grateful for any suggestions you guys may have!

 

[Korhil78]

Well, it seems like you have tried everything. I don't know who you are so I don't know how experienced you are as a shooter. Do you know someone that is quite a good shooter? If so, let them try shooting the same loads that you think are most accurate in your rifle and see how he fairs. Then if he shoots around the same size groups, you will know that it wasn't you mucking it up.

If it still doesn't look good, I would send it back to Snowy Mountain Rifles and have them take a look at it and shoot it.

 

[WyoElk2Hunt]

My load is:
Lapua brass
Fed 215 Primer
90 grs H1000
300 gr Berger Hunting VLD
2875 FPS
COAL is 3.080
Works great for me.gun)

 

[Korhil78]

My load is:
Lapua brass
Fed 215 Primer
90 grs H1000
300 gr Berger Hunting VLD
2875 FPS
COAL is 3.080
Works great for me.gun)

You are getting 2875 fps out of 90 gr of H1000? How long is your barrel?

 

[WyoElk2Hunt]

It is 28 inches. McMillan EOL LRH rifle.

 

[Bigcat_hunter]

What is your trigger pull weight? I have my long range rig set at 14oz. A heavy pull will notnhelp groups.

 

[kdumph]

Trigger should be around 2.5 since this is my hunting rifle. It's heavy, but manageable. I really don't think it's me as the shooter either. I used to shoot 3-postion at the jr olympic level, and I'm also shooting from a solid two sandbag system that takes the hard work out of it. I open to letting anyone else shoot it in Colorado though.

 

[kdumph]

My load is:
Lapua brass
Fed 215 Primer
90 grs H1000
300 gr Berger Hunting VLD
2875 FPS
COAL is 3.080
Works great for me.gun)

What is your max COAL on that gun for the VLD or to the lands I mean? I'm almost a full inch off from your measurements? 3.850 for the OTMs and 3.790 for the SMKs on my rifle.

 

[kdumph]

Also have anyone seen big changes between Retumbo and H1000 or RL25?

 

[WyoElk2Hunt]

What is your max COAL on that gun for the VLD or to the lands I mean? I'm almost a full inch off from your measurements? 3.850 for the OTMs and 3.790 for the SMKs on my rifle.

My mistake my COAL is 3.800 not 3.080

 

[den]

do you have your groups on that target documented to what groups are what ? seating depths, powder charges , bullet ect....

 

[kdumph]

I do the photo is all of SMK's, but the bergers had the same performance. The top right group of 6 were a ladder test at 3.950.
Moving left, 90gr at 3.950 (was the first load I tested when I was working with the bergers and had performed a tad better. So I loaded four.
Moving down, 89gr 3.979
Down Again, 89gr 3.974
Moving left, 89gr 3.969
Moving down, 89gr 3.958

 

[den]

IMHO the top three of that ladder look promising to me if that is three different powder charges

 

[kdumph]

I want to say, one of those was a called flyer in that top three while shooting the ladder so I didn't pay it much heed.