338 LM Load Development

[jtkite]

Running a Remington 700 PSS .338 LM, 26" barrel, 1:10"...
Testing out the 245gr Bore Tech V3's and the 250gr Lapua Scenars...
I need suggestions on starting grain weights for this load development. All are on Lapua brass, and Hodgdon Retumbo powder. I'm new to this, so any suggestions are helpful.

 

[TDaly25]

Re: 338 LM Load Development

With a 1:10" twist I'd be shooting something heavier. I personally shoot the 300Gr. SMKs over 90.5 grains of Retumbo with great results

 

[ChrisGarrett]

Re: 338 LM Load Development

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: USMC 03</div><div class="ubbcode-body">Running a Remington 700 PSS .338 LM, 26" barrel, 1:10"...
Testing out the 245gr Bore Tech V3's and the 250gr Lapua Scenars...
I need suggestions on starting grain weights for this load development. All are on Lapua brass, and Hodgdon Retumbo powder. I'm new to this, so any suggestions are helpful. </div></div>

If the Bore Techs are solids and I think they are, be careful shooting them through a traditional bore.

They don't compress, like typical lead core bullets.

There's a ton of info here and on the Reloading Depot tacked at the top of this forum, so just do a search with 338LM + Retumbo and you'll have weeks of reading.

I like Hodgdon 4831SC, VV-165, VV-170 and H-1000 with my 250s.

Chris

 

[jaycoux]

Re: 338 LM Load Development

I use 250 scenars in a TRG 1 in12 twist. Retumbo is the only powder I have ever used. I settled on 94.8 grains and Fed 215M primers. This produces about 2940 or so out of my rifle. I've never shot past 1000 yards with it but it does very well to that distance. Please work up carefully and good luck.

Jay

 

[redbullitt]

Re: 338 LM Load Development

I have 87.5 grains or reloder 25 under 300 grain smks. Shoots very well for me out of 28 inch barrel 1/10 twist.

Any reason you are using the 250s? Just curious.

 

[mdmp5]

Re: 338 LM Load Development

Nothing wrong with the 250s at all. I use 97 of H1000 under 250 SMKs. For the 300s, I am still in the process of working up a load, but 94 of Retumbo does ok. I am gonna try to find the sweet spot for H1000.

 

[TimResin]

Re: 338 LM Load Development

what about RL 25? Start at about 86 grains?

 

[jonaddis84]

Re: 338 LM Load Development

Do you guys think Retumbo is a preferred choice over a powder like H1000 for 26" and under barrels?

 

[ChrisGarrett]

Re: 338 LM Load Development

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jonaddis84</div><div class="ubbcode-body">Do you guys think Retumbo is a preferred choice over a powder like H1000 for 26" and under barrels? </div></div>

Retumbo is a good slow powder. So is H-1000. Get a few powders, including the ones I mention above and let your gun tell you what it likes the best. RL-25 is another to consider, if you're not shooting at the temperature extremes.

Chris

 

[Sendero_Man]

Re: 338 LM Load Development

H4831SC does great with the 250 Scenars

 

[jonaddis84]

Re: 338 LM Load Development

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ChrisGarrett</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jonaddis84</div><div class="ubbcode-body">Do you guys think Retumbo is a preferred choice over a powder like H1000 for 26" and under barrels? </div></div>

Retumbo is a good slow powder. So is H-1000. Get a few powders, including the ones I mention above and let your gun tell you what it likes the best. RL-25 is another to consider, if you're not shooting at the temperature extremes.

Chris </div></div>

Is there a slightly faster extreme powder that might work better in a shorter bbl? I know I need to try a few, just trying to get ideas for what to try. Thanks.

Not trying to hijack the thread, I noticed OP is shooting a 26" stick also and thought he may benefit from my questions as well.

 

[jaycoux]

Re: 338 LM Load Development

There was a discussion a few years back maybe where Zak Smith and Ray Sanchez from demigod were working up loads for a TRG and AIAWSM. If I recall Zak said the H1000 did poorly at the longer ranges IN THEIR RIFLES. Not sure what your app is with this rifle but I would expect it isn't 500 yds and in...

This may be relevant info for you or not but thought I would throw it out there. They had good solid info on their loads with a few different powders which they tested out to 1700 yards.

Let me know if you can't find that thread and ill look it up fpr you

Jay

 

[jamiebob]

Re: 338 LM Load Development

I have a few question just load for my trg 42 300 smk and remtumbo
90.5 gr fps=. 2711, 2697, 2698, 2695
91 gr fps =. 2666, 2666, 2669
91.5 gr fps= 2661, 2676, 2669
92 gr fps = 2725, 2720, 2731

Not sure why there was no fps increase with the 91 gr loads?

 

[rymart]

Re: 338 LM Load Development

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: TimResin</div><div class="ubbcode-body">what about RL 25? Start at about 86 grains? </div></div>

RE-25 shot well for me, until I tried H1000. I ended at 86 grains of RE-25 with slight bolt lift at 87 grains. In the end RE-25 was too temperature sensitve for my needs. That became painfully apparent on a late elk hunt in below zero temps.

I run 92 grains of H1000 in a 27" Bartlein barrel with 300 gr SMK's jumped 0.020". Average velocity is 2805 fps. The load is somewhat on the hot side, but I'm pretty sure there is an accuracy node for my rifle at this powder charge. I get single digit SD and ES with this load. Took it out to 1000 yards on paper last weekend... shot four 3-shot groups in variable 10 - 15 mph crosswinds. First shot was 4 inches from the center

, best group was 9", with 1/2" of verticle. Worst was 15" with 5" of verticle. All shots were on paper

. Love that low ES...

 

[Dogtown]

Re: 338 LM Load Development

Retumbo is definitely a safe bet for this class of cartridge, especially if you push the 300gr bullets. That powder is slow enough that you can get good velocity out of them without over doing the pressure.

But don't discount the 250 Scenar. They are easily good to a mile and perform really well if you push them fast (2900-3000fps). RL25 and Retumbo are also good for these but I now prefer N560 for them. With that powder I've gotten them close to 3100fps safely and at that speed the gap between them and the 300s starts to go away.

 

[psinclair]

Re: 338 LM Load Development

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sendero_man</div><div class="ubbcode-body">H4831SC does great with the 250 Scenars </div></div>

+1....also try VVN560 for the 250's. It gave me the most accuracy and lowest ES. 1-9.75" Bartlein 5R @ 28". I've gotten 3100fps with the 250gr scenar and VVN560.

Dogtown is right, the 250 at those speeds will do anything a 300gr will at 2700fps and then some.

 

[Cigarcop]

Re: 338 LM Load Development

Any of u guys using VVN570 with the Lapua?.....I've used it in my Norma with good results but not the Lapua.