Need help on .338 Lapua 300 grain loads

[bm11]

I am not new to load development, only new to loading for .338 Lapua. I have been having a bit of difficulty working up a good load for it, and time is getting down to the wire, so I need some help.

I am taking Gunsite's ELR class in the beginning of October, which means I have less than a month to work up a load that will be 2,000 meter proficient.

The rifle I am using is a brand new Sako TRG-42, with a 1 in 10 twist barrel. Unless a 10 twist won't shoot 300 grain bullets, I have no interest in shooting 250 grain bullets.

I bought new Lapua brass, as well as some Berger 300 grain Hybrid bullets and some 300 grain Scenars. I would prefer to run the Berger bullets because they have the highest BC of commonly available 300 grain bullets. I also had on had about 8 pounds of RL-25, so I would prefer to use it, though I will buy an alternate powder if need be.

I have been doing load development at 230 yards and 600 yards. The 230 yard range is more convenient to me and easier to get a chronograph set up, but obviously 600 yards is a better indicator of long range proficiency.

Now comes the issue: I have been having an impossible time getting any load I have tried to shoot well with any level of consistency. I thought I had a decent load with the 300 grain Bergers, using 87.0 grains of RL-25, as upon initial testing, it shot a 1 inch 5 shot group at 200 meters with an average velocity of 2600 FPS and an acceptable ES of around 20FPS over 5 rounds.

Further testing at 600 yards produced one good group of about 3 inches at the original seating depth of 3.745" OAL, which is about the max the magazine will handle, and crappier groups of around MOA at any shorter seating depth.

Thinking I had found my load, I tested it again over the chrono at 230 yards, and while the velocity was consistent, the accuracy was poor. One good group and the other two terrible. I also tested a couple loads using 300 grain Scenars over 86.0 grains and 87.0 grains of RL-25, and the accuracy was very poor.

So, this post is a bit information overload but I didn't know how much time I'd have to come back and check it during the day so I wanted to fill in as much as possible.

Any advice will be appreciated as I am getting desperate- I don't have much time before I need to load about 250 rounds and ship them out to Arizona.

Thanks,

-Bob

 

[ksthomas]

Re: Need help on .338 Lapua 300 grain loads

Hi Bob,

I'd suggest making a switch to the Hodgdon H1000 powder for two primary reasons. One, it's a combination that always gave me terrific accuracy in the 338LM, with both 250 and 300 grain bullets, and two, it's not nearly so temperature sensitive as the RL25 you're using now is. Basic issue of a single based powder (and one of the Hodgdon "Extreme" powders at that) being compared to a double base powder; you'll almost always see more velocity and pressure variations from the double based powder. Going from "home" to the AZ desert, that's something that needs to be taken into consideration.

Give it a try, and I think you'll find it's a winner.

 

[sinister]

Re: Need help on .338 Lapua 300 grain loads

Bob, I've shot Reloader 25 and I don't like it. I agree with Kevin on the Hodgdon Extreme (re-branded Australian import) powders.

H1000 (Thales/Australian Defense Industries AR2217) is a good powder, while my personal favorite in a TRG-42 is Retumbo (ADI AR2225). The Hodgdon site has this data for 300-grain Match Kings:

300 GR. SIE HPBT Hodgdon H1000 .338" 3.600" -- 83.0 start 2383 fps 43,200 CUP -- 92.0Compressed Max 2590 53,000 CUP
300 GR. SIE HPBT Hodgdon Retumbo .338" 3.600" -- 85.0 start 2376 fps 41,100 CUP -- 94.0Compressed Max 2654 53,400 CUP

My load (for 300-grainers) is 94.0 Retumbo thrown on an RCBS Chargemaster. I use Lapua brass (I also have some BeLL but have given away Norma and Hornady cases as too soft) and Remington Large Rifle Magnum primers. I found in New Mexico and here in Utah at 4500 - 5000 feet Mean Sea Level the Sierras generally run out of steam around 1750 Meters, the Bergers around 1850, and the Lapuas past 2000.

I shoot way more 250s than 300s.

Good luck -- it sounds like Gunsite will be fun.

 

[ChrisGarrett]

Re: Need help on .338 Lapua 300 grain loads

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bm11</div><div class="ubbcode-body">I am not new to load development, only new to loading for .338 Lapua. I have been having a bit of difficulty working up a good load for it, and time is getting down to the wire, so I need some help.

I am taking Gunsite's ELR class in the beginning of October, which means I have less than a month to work up a load that will be 2,000 meter proficient.

The rifle I am using is a brand new Sako TRG-42, with a 1 in 10 twist barrel. Unless a 10 twist won't shoot 300 grain bullets, I have no interest in shooting 250 grain bullets.

I bought new Lapua brass, as well as some Berger 300 grain Hybrid bullets and some 300 grain Scenars. I would prefer to run the Berger bullets because they have the highest BC of commonly available 300 grain bullets. I also had on had about 8 pounds of RL-25, so I would prefer to use it, though I will buy an alternate powder if need be.

I have been doing load development at 230 yards and 600 yards. The 230 yard range is more convenient to me and easier to get a chronograph set up, but obviously 600 yards is a better indicator of long range proficiency.

Now comes the issue: I have been having an impossible time getting any load I have tried to shoot well with any level of consistency. I thought I had a decent load with the 300 grain Bergers, using 87.0 grains of RL-25, as upon initial testing, it shot a 1 inch 5 shot group at 200 meters with an average velocity of 2600 FPS and an acceptable ES of around 20FPS over 5 rounds.

Further testing at 600 yards produced one good group of about 3 inches at the original seating depth of 3.745" OAL, which is about the max the magazine will handle, and crappier groups of around MOA at any shorter seating depth.

Thinking I had found my load, I tested it again over the chrono at 230 yards, and while the velocity was consistent, the accuracy was poor. One good group and the other two terrible. I also tested a couple loads using 300 grain Scenars over 86.0 grains and 87.0 grains of RL-25, and the accuracy was very poor.

So, this post is a bit information overload but I didn't know how much time I'd have to come back and check it during the day so I wanted to fill in as much as possible.

Any advice will be appreciated as I am getting desperate- I don't have much time before I need to load about 250 rounds and ship them out to Arizona.

Thanks,

-Bob </div></div>

I shoot a 1:12" TRG and so I'm confined to mostly the 250s at 0 ASL here in Miami.

2000m is going to be hard to do with a TRG-42, even with a 1:10" twist and 300gr bullets. We just start running out of case capacity when loading to magazine length.

You're stretching the envelope with the 27 1/8th inch TRG-42 338LM, although long shots have obviously been made in the field.

The Fins were getting to 2000m with their 250gr loaded ammo, but they really tested the snot out of the 1:12 42s during their T&E of the Sakos.

If you can get the 250s up to 3000 fps and you can, easily, you might just find that their added velocity perhaps offsets the lower speeds you're getting with the 300s, albeit with the 'dirtier' 250s.

Maybe try Retumbo, or H-US 869? Maybe VV N-570, if you can find it.

Chris

 

[ksthomas]

Re: Need help on .338 Lapua 300 grain loads

I didn't mention Retumbo, but probably should have. It's another excellent choice for this combo. Good call!

 

[bm11]

Re: Need help on .338 Lapua 300 grain loads

Ok, so H1000 and Retumbo, that's what I was thinking also. I'll pick some up and see if I can't get better results!

 

[jagged77]

Re: Need help on .338 Lapua 300 grain loads

I've been having similar problems, thought I'd found a good load with 300 scenars and n570, went to verify it and got poor results. I've got some H1000 to try so hopefully will fare better, retumbo seems to be also a good choice.

 

[hessian]

Re: Need help on .338 Lapua 300 grain loads

I have had very good results with 91 gr. N570 and 300 gr. OTM Bergers.

 

[jkonzal]

Re: Need help on .338 Lapua 300 grain loads

I have Barrett's 98B with 1:10 twist. Barrett told me NOT to shoot 300gr bullets thru it. With that twist, they said to stay with the 250's.

 

[turbo54]

Re: Need help on .338 Lapua 300 grain loads

My TRG42, with 1-12 barrel, is abso-fucking-lutely lights out with:

90.5 Retumbo
300smk
As long as possible but still fit the magazine
cci magnum primer
2668fps over an Oehler 35p

This load printed a 1" group @ 600 yards

I've found TRGs to shoot everything well.

Any chance it's just you having trouble firing a 338?

 

[rommelj]

Re: Need help on .338 Lapua 300 grain loads

Use Retumbo if you want to shoot the 300. Excellent velocity and not sensitive to temperature change. I use 95 grains with 300 SMK in my 338 Lapua AI. Velocity is around 2850 fps from a 30" 9.3 twist Broughton.

25 shot group @ 1K

 

[sinister]

Re: Need help on .338 Lapua 300 grain loads

Nice elevation -- X-ring high and just a few leakers from wind. Good job holding charge consistency.

A 243-13X of 250 at a grand.

 

[mavrick10_2000]

Re: Need help on .338 Lapua 300 grain loads

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: turbo54</div><div class="ubbcode-body">My TRG42, with 1-12 barrel, is abso-fucking-lutely lights out with:

90.5 Retumbo
300smk
As long as possible but still fit the magazine
cci magnum primer
2668fps over an Oehler 35p

This load printed a 1" group @ 600 yards

I've found TRGs to shoot everything well.

Any chance it's just you having trouble firing a 338? </div></div>

Turbo,

That's good to see. I believe the issue for a 1:12 twist is pushing beyond transonic and keeping stability. 600 yds or even 1K won't test that. And the ELR class will be pushing to 2K.

Bob I'd try the H1000, retumbo or N570 (although tough to find). PGS had great success with H1000 and the 300's. Might want to ping him or SM. Pref's would go to H1000. Have read reports from Retumbo users that it's a bit dirtier burn.

 

[bm11]

Re: Need help on .338 Lapua 300 grain loads

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: turbo54</div><div class="ubbcode-body">

Any chance it's just you having trouble firing a 338? </div></div>Absolutely. I know that I do have an unresolved recoil/blast anticipation issue. However, I strongly believe I have seen this rifle throwing shots off that were not shooter related.

As an update: I picked up some Retumbo locally, I have not yet locally located some H1000. Before switching to powders I did take the time to find where the lands were in relation to seating depth and determined that at max mag length my Bergers were jumping .120, and that I am able to jam Scenars and still be under mag length. Loading Scenars to .010" deeper than where land engraving can last be seen, that I am getting better, more consistent accuracy than I was. The Scenars also launch at a higher velocity per charge weight than the Bergers, and seem to show less pressure. 88.0 of R25 grains gave me 2710 FPS with low ES and decent accuracy, so I will pursue this load further, as well as trying the Retumbo.

 

[Lowlight]

Re: Need help on .338 Lapua 300 grain loads

300's are not the end all that people claim, because most of that is on paper,

Skip the 300's and use the Hornady 285's or 250 Scenars.

I wouldn't waste your time with the 300's

 

[bm11]

Re: Need help on .338 Lapua 300 grain loads

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">300's are not the end all that people claim, because most of that is on paper,

Skip the 300's and use the Hornady 285's or 250 Scenars.

I wouldn't waste your time with the 300's </div></div>Frank,

Could you please elaborate further? I remember you saying the 285's were the best performers at distance at the ELR class, could you please expand on why I should give up on the 300's? Too hard to get to shoot?

 

[ChrisGarrett]

Re: Need help on .338 Lapua 300 grain loads

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bm11</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">300's are not the end all that people claim, because most of that is on paper,

Skip the 300's and use the Hornady 285's or 250 Scenars.

I wouldn't waste your time with the 300's </div></div>Frank,

Could you please elaborate further? I remember you saying the 285's were the best performers at distance at the ELR class, could you please expand on why I should give up on the 300's? Too hard to get to shoot? </div></div>

Not speaking for LL, but I see this happen a lot around here. Kind of a spin on the 'Bullet Of The Month' phenomenon.

It's tough to get the 300s up to speed--2800+ fps, where that speed offsets the performance you can get with the 250s travelling upwards of 3000+ fps, which really isn't hard to do with most of the 26" and 27" barrels that are common.

Guys shooting 28", 30", 32" barrels can get those 300s up past 2900 fps and get them to sail.

Add to all of this, loading the 300gr bullets to typical magazine length and well, you're just chewing up case capacity, adding insult to injury. Also, being 20% heavier than the 250s, the 300s will thump harder and cost you more money.

You just have to run the numbers and see what works best at whatever speed you can get those bullets up to (while still retaining accuracy). Often times, the 250s will actually outperform the 300s at 'real world' velocities.

There's a thread over on AR15.com. Many are screaming about shooting the 208 AMAX out of the 308Win. Why? It's got a great BC and must be the cat's meow.

Problem is is that it's a heavy bullet for the cartridge and guys that do get it to shoot well, are using RL-17 and shooting at a fairly high altitude, where the air is thinner.

Not saying that the 300s aren't a great bullet, but the 250s can be easier to shoot for most peoples' setups.

The Finnish army snipers were quite content to stick with the 250s and did pretty well when approaching 2km. If they had thought that the 300s whould have given them an edge, they would have used them in their T&E, but they didn't.

Chris

 

[bm11]

Re: Need help on .338 Lapua 300 grain loads

Chris,

I just ran the numbers and you are 100 % correct. I could have sworn I ran them before and found a huge advantage with the 300's, but damn, the numbers are really close at 4000 DA shooting a 250 Scenar at 3000 vs a 300 at 2710, all the way out to 2000 yards.

 

[ChrisGarrett]

Re: Need help on .338 Lapua 300 grain loads

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bm11</div><div class="ubbcode-body">Chris,

I just ran the numbers and you are 100 % correct. I could have sworn I ran them before and found a huge advantage with the 300's, but damn, the numbers are really close at 4000 DA shooting a 250 Scenar at 3000 vs a 300 at 2710, all the way out to 2000 yards. </div></div>

Always run the numbers and be honest with yourself.

We all like to tell others how fast we get our shit up to and how low our SDs are and well, sure...I'd want to peak over your shoulder for an hour.

Now, I will say, I was proposing that the 155 Scenar at 2950 fps, could 'out wind' the 208 AMAX at even 2450 fps and it can't, so I was wrong on that front.

Still, I don't think that the 208s will shoot terribly well for me even using RL-17 and a 1:10 Savage that's shooting well now, with everything up to the 190 SMKs, because I'm at 0 ASL and the air is generally thicker, due to humidty.

So, ultimately, it comes down to inherent accuracy for any particular bullet, fired through a particular 'system'. I'd rather have a 1 MOA bullet, giving up .5 MOA in wind, than to have a 2 MOA bullet, but be that much better in wind deflection...but I'm just a hack.

Chris

 

[bm11]

Re: Need help on .338 Lapua 300 grain loads

Chris,

I couldn't get the 208's to shoot better than 1 moa for me, where my 155 load shot .5 moa average, and I mean a real average over the course of 5x5 shot groups, so I certainly am with you there. An "on paper" advantage doesn't mean shit if the gun shoots like shit.

I'm running out of time, and while I haven't given up on the 300's I need to order up some 250's now so that I have them on hand if needed.

-Bob

 

[Lowlight]

Re: Need help on .338 Lapua 300 grain loads

Chris answered for me as I am traveling and just posted between layovers.

If you want heavy no more than the 285's, but you can't beat the 250 Scenars loaded to mag length. I have shot them beyond 2k and they work.

There is a reason very few if anyone serious shoots the 208, especially because we aren't using 30" barrels. Want to use a 208, get a 300WM, want to go heavier than 285s, get a different rifle, same thing.

 

[turbo54]

Re: Need help on .338 Lapua 300 grain loads

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mavrick10_2000</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: turbo54</div><div class="ubbcode-body">My TRG42, with 1-12 barrel, is abso-fucking-lutely lights out with:

90.5 Retumbo
300smk
As long as possible but still fit the magazine
cci magnum primer
2668fps over an Oehler 35p

This load printed a 1" group @ 600 yards

I've found TRGs to shoot everything well.

Any chance it's just you having trouble firing a 338? </div></div>

Turbo,

That's good to see. I believe the issue for a 1:12 twist is pushing beyond transonic and keeping stability. 600 yds or even 1K won't test that. And the ELR class will be pushing to 2K. </div></div>

Disagree. Stability goes up with range, not down. The chrono claims 2668. My actual dope in JBM works out to ~2750. Regardless, their subsonic @ 1760 yards, and I have no predictability issues out there. I've done this down to a DA of-1000ft. Actual conditions were ~1000ft ASL, 35°F.

Not saying 300s are "the best", only reporting my experiences with them. While 1:12 is supposedly not good enough for the 300smk, it works just fine for me, even trans/subsonic.

Another load that shot beautifully for me was 85.5gr RL22, 250scenar loaded to may length. This was the previous owners workup, and I don't know how fast it was.

 

[mavrick10_2000]

Re: Need help on .338 Lapua 300 grain loads

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: turbo54</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mavrick10_2000</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: turbo54</div><div class="ubbcode-body">My TRG42, with 1-12 barrel, is abso-fucking-lutely lights out with:

90.5 Retumbo
300smk
As long as possible but still fit the magazine
cci magnum primer
2668fps over an Oehler 35p

This load printed a 1" group @ 600 yards

I've found TRGs to shoot everything well.

Any chance it's just you having trouble firing a 338? </div></div>

Turbo,

That's good to see. I believe the issue for a 1:12 twist is pushing beyond transonic and keeping stability. 600 yds or even 1K won't test that. And the ELR class will be pushing to 2K. </div></div>

Disagree. Stability goes up with range, not down. The chrono claims 2668. My actual dope in JBM works out to ~2750. Regardless, their subsonic @ 1760 yards, and I have no predictability issues out there. I've done this down to a DA of-1000ft. Actual conditions were ~1000ft ASL, 35°F.

Not saying 300s are "the best", only reporting my experiences with them. While 1:12 is supposedly not good enough for the 300smk, it works just fine for me, even trans/subsonic.

Another load that shot beautifully for me was 85.5gr RL22, 250scenar loaded to may length. This was the previous owners workup, and I don't know how fast it was. </div></div>

Turbo,

We're referring to two different conditions. You're referring to the bullet "going to rest" shorter range I'm referring to when the bullet transitions from super to subsonic which will vary between 1600 to 1700 plus yds. There's a reason 1:10 or faster twists exist for ELR and it's not all marketing. YMMV.

Glad to hear the 300's are working for you.

 

[pharoh1]

Re: Need help on .338 Lapua 300 grain loads

Another vote for the hornady 285's. There is no reason to look any further.

 

[bm11]

Re: Need help on .338 Lapua 300 grain loads

Why 285's? It doesn't seem as though the 15fps would net you much velocity, but it does come with a big BC penalty. What am I missing?

 

[Mk4]

Re: Need help on .338 Lapua 300 grain loads

Powder Valley is out of 285's. Who else has a good price on them?

Noticed that Midway was out as well.

 

[pharoh1]

Re: Need help on .338 Lapua 300 grain loads

BC isn't everything. I'm pushing 285 hornady out of a 26" barrel at 2800fps with a 93gr charge of retumbo. I played extensively with 300gr scenars, and could only get them to around 2750fps, and that was a hot load (very hot). Recoil was much higher, accuracy was harder to achieve, and the bullets more expensive.

Others might have a different opinion, but the 285 from hornady seems to be the perfect bullet for me.