338 Lapua Improved?????

[rigmaster10]

I just finished building a 338 Lapua 40 degree shoulder. Im looking for some load data. Has anyone built one before. I built mine on a 32" broughton barrel. Remington 700 action. On an XLR stock. I am going to run 300 gr. SMK's. I think maybe Retumbo, N570 or RL 33 powder.

 

[Dogtown]

I think you'll get more out of RL33 with that combo.

 

[P7id10t]

I just finished building a 338 Lapua 40 degree shoulder. Im looking for some load data. Has anyone built one before. I built mine on a 32" broughton barrel. Remington 700 action. On an XLR stock. I am going to run 300 gr. SMK's. I think maybe Retumbo, N570 or RL 33 powder.

SAAMI spec on the 338LM shoulder is a cone of angle 39°59'48", which for all practical purposes is 40°. Are you saying you built one with a 80° cone section? If so, I'll bite: what are you expecting to gain out of that 'cept another grain or two of powder capacity?

On powders, IMO any will do. BUT -- if what we read on this board is true, VV is as good as dead, so forget N570.

With your barrel length, I'm interested in seeing what you get out of both Retumbo and RL33.

 

[rigmaster10]

Im thinking so too. Just wondering if anyone else has done it. Hoping to get 3,000 fps with it.

 

[FN in MT]

Would like to see a shot of the standard and improved rd side by side.

 

[CapDog]

There was smith out this way building quite few of those. The goal was higher velocity specifically with the 300gr bullets and pro-longed case life as the .338 Lapua brass isn't the cheapest out there. Next time I bump into him I'll ask what the velocities he was getting and how many loadings out of the brass.

 

[rigmaster10]

I have fireformed some brass already Ill put some pictures on here. Its a big difference. More than I was expecting. The only problem im having is feeding issues.

 

[rigmaster10]

 

[rigmaster10]

Brass is fireformed and im getting 2980 FPS and no pressure signs. I could run it harder but it shoots 1/4 moa. I think I will leave it alone.

 

[RugerSlinger]

That's awesome. How much more powder can you stuff in there? Looks like atleast a few. Glad its working out, how's the feeding issue?

 

[Rookie]

What powder and charge weight did you settle on? That's fantastic accuracy.

 

[rigmaster10]

106 grains of Rl-33. No pressure signs at all. And about the feeding issues. We milled front rib out of the mag and tweaked it a bit. Now it works pretty well

 

[Donavonc2000]

Great results, mine won't print 300s so I will try RL 33 if I can find some. May be a bit slow for my 27" though but thanks for posting your results it gives me a new avenue to try.

 

[Desert Fox]

I use 96 grains of Retumbo. Velocity is around 2875 on a 30" Broughton 5C. I can probably push it to 2900 fps + but no need for it though.

Here's a side by side comparison.

 

[Jeffvn]

My 338 LM Improved runs:

2,940 w/ 98 gr. Retumbo;
3015 w/ 100 gr. VV 570. Not sure how long the VV will be available, so I'm looking to test RL33 in the near future.

Jeffvn

 

[rigmaster10]

I'm Running 3000 Fps With 106 Gr. O RL33

 

[turbo54]

If you're going to bother with hotrodding 338LM, with fireforming, custom reamers, dies etc etc, why would you use 300smk bullets?

 

[P7id10t]

If you're going to bother with hotrodding 338LM, with fireforming, custom reamers, dies etc etc, why would you use 300smk bullets?

Because they work, as well as Berger OTMs or Scenars, or even farking Hornady SP's.
At 100+ grains, I'd look at using WC870 or such.

At 2900 fps or higher and no pressure problems, I'm interested.
Kinda reminds me of the Weatherby 378-338 w/o the belt.

 

[rigmaster10]

Because they work, as well as Berger OTMs or Scenars, or even farking Hornady SP's.
At 100+ grains, I'd look at using WC870 or such.

At 2900 fps or higher and no pressure problems, I'm interested.
Kinda reminds me of the Weatherby 378-338 w/o the belt.

I agree Sierra makes a fine bullet. As does Berger and Hornady. If Turbo 54 means why not use Copper solids. I don't use them because if I do. Ten rifles using them at 1000 rounds a piece that equals $5,000.

 

[rigmaster10]

I just read my first post. I guess I said I use. SMK's my mistake in this rifle I use 300 gr Berger Hybrid's. Sorry about the mix up.

 

[mdmp5]

I use 96 grains of Retumbo. Velocity is around 2875 on a 30" Broughton 5C. I can probably push it to 2900 fps + but no need for it though.

Here's a side by side comparison.

Man that improved 338 case sure is pretty

 

[Sowastrong Industries]

Decided to try out RL33 with some hunting VLD's. Been using 98.7gr Retumbo with 300smk from 30" getting 2920fps but with pressure signs.

RL33 102gr
berger 300gr hunting VLD
3.844" OAL with .025" jump to lands
CCI lg rifle mag
ave 2943 with SD of 4
4 rounds touching at 100yds

 

[Desert Fox]

Decided to try out RL33 with some hunting VLD's. Been using 98.7gr Retumbo with 300smk from 30" getting 2920fps but with pressure signs.

RL33 102gr
berger 300gr hunting VLD
3.844" OAL with .025" jump to lands
CCI lg rifle mag
ave 2943 with SD of 4
4 rounds touching at 100yds

Yup! 98.7 grains of Retumbo is probably smoking. I was not able to load above 95 grains until after around 2000 rounds went through my barrel.

 

[rigmaster10]

Seems like all of these rifles are performing about the same. And getting great results. Anyone else have any feeding issues. I have improved mine. But its still not Silky Smooth.

 

[DAVETOOLEY]

Seems like all of these rifles are performing about the same. And getting great results. Anyone else have any feeding issues. I have improved mine. But its still not Silky Smooth.

Never will be smooth with the 40* shoulder. 3000 FPS is all you can get out of that case. Brass will live longer at 2925-2950 FPS and probably shoot better.

 

[rigmaster10]

Rifle shoots 1/4 moa. Im leaving it right where it is in the 2980-3000 fps range. If it burns up a throat and some brass so be it. Ill just chuck it in the lathe and take a little off.

 

[2G5MK]

Rigmaster10:

Have you had any issues other than you early feeding issues with the 700 Action? I was in the middle of a 9.53 Saturn build when several people suggested that I would be pushing the Remington Action too hard. I stopped the project for a bit, but now I am having second thoughts. How many rounds do you have through you rifle? The accuracy sounds insane.

 

[rigmaster10]

There were some feeding issues in the beginning. But with some mag work and polishing feeds fine now. And as far as pressure its a matter of pressure x area x mass formula. Actual force on the action has not changed. Yes there is more recoil compared to a standard Lapua mag based on the amount of powder burned. Just look at things in terms of a piston. Going to 375 in the same mass of bullet will exert far more force on the action than a smaller diameter bullet of the same mass.

 

[rigmaster10]

This thread sure died fast.