Fastest powder you've had work in 338 Lapua?

[Bronco302]

My current favorite load is RL-33 with the 285 A-max (2880 fps out of a 30" barrel), but have used 4831sc, H-1000 for 250 gr. and RL-22 with the 300 gr. Berger.

 

[dkhunt14]

I have an Improved version. I used Reloader25, H1000, US869 and Reloader 33. I shoot all 300 grian bullets but did test lighter ones. The 338 Lapua case shines with Reloader 33. I got more accuracy, speed and a whole lot less pressure with it. It seems to hold velocity well with temperature changes also. Mine is a hunting gun so I don't shoot it when it's real hot out. But temperature swings in the winter time of 40 degrees did not seem to change elevation much.

We also used that powder in 2 different 338 Ultras and a 338-378 and it worked with the same results. Matt

 

[alphapygmy]

Score! Local hardware shop got in a couple 8 pounders of RL33 and I nabbed one.

 

[davidjoe]

There’s “fast” burning and fast bullet velocity. You probably can’t beat RE 33 for the highest velocity for any given amount of peak pressure on the case head, with 300’s.

But that long push through the whole barrel length can sure heat it up in long shot strings. It’s easy on the brass while maniacal on the bullet, but they won’t blow up. The barrels can wear though. Still, for hunting or plates where cumulative heat is controllable, it really moves them out fast and accurately.

I found that h1000 doesn’t overheat the barrel in Fclass strings, but is only going to yield moderate velocity, where its best accuracy is, and brass life. Getting the caliber to out score a Saum or even .284 sure is a challenge though,

 

[alphapygmy]

This will be a rifle for plates so not too worried about heat build-up. 338L for F Open? Yikes, I'm not man enough to try that...

 

[DiffEQ]

@alphapygmy , I still have those 12 x 12 x 1/2" AR500 plates we talked about when I bought the three barrels from you. Lemme know if you want one. You're set with RL33.... I have a few lbs of it but haven't tried it yet.

Fastest I've tried was Alliant 4000-MR. When I bought it, was touted as "about the speed of H1000". I would max pressure at 85gr with 300 Bergers. RL25 maxed out well below desired velocities. I tried RL26, loading it from data for RL25. A mistake - good thing I started low. It is a much higher energy density and maxed out below RL25 loads. I'd have to dig to find that range notebook.

 

[alphapygmy]

@alphapygmy , I still have those 12 x 12 x 1/2" AR500 plates we talked about when I bought the three barrels from you. Lemme know if you want one. You're set with RL33.... I have a few lbs of it but haven't tried it yet.

Love to have a plate! PM sent

 

[dkhunt14]

Starting to work up my 338 Lapua and having good luck with RL33 and Hornady 285's and Berger 300's. I only have a few pounds of RL33 and no more available so I'm looking for a backup powder. I have some H4831SC but that's about the next slowest thing I have. I can get a little RL26 locally but no H1000 or Retumbo. What faster powders have you ran in your 338L with the heavier bullets?

33 Is the powder for the 338 Lapua, especially with the heavy bullets. I have shot a variety of powders in my IMP version. RELOADER25 was ok for accuracy but I couldn't get the velocity and it was real hard on the brass. H1000 was a little better but still couldn't get the velocity I wanted and it was hard on brass. Anything faster then those powders and you won't be happy. At the price of the brass, I would really try to find Reloader33. I don't think you will be happy with the performance of anything else. Matt

 

[B23]

Mine is a 40 degree shoulder Improved version and is pretty long throated for the 300's. I have a fireforming load with RL25 that shoots in the 3's but that's all I use it for because I don't want to waste any of the powders I like on fireforming.

In formed cases w/300's I've used H870, US869, N570, RL33 and they produced the best speed in that order as well. As you can see none of which are fast powders and one of them they don't even make anymore.

 

[ronemus]

Has anybody tried IMR-7977? The load data on Hodgdon's site looks promising, but I haven't heard of anybody using it. I want to try something other than RL-33; I have a good supply of it, but all the groups are MOA+. I think the factory RPR barrel may be part of the problem, but it's going to be a while before the replacement comes in.

 

[dkhunt14]

Has anybody tried IMR-7977? The load data on Hodgdon's site looks promising, but I haven't heard of anybody using it. I want to try something other than RL-33; I have a good supply of it, but all the groups are MOA+. I think the factory RPR barrel may be part of the problem, but it's going to be a while before the replacement comes in.

I woukd try the bullets in the lands. My Lapau's all shoot better that way. Matt

 

[Alex Wheeler]

We have been working with the 338 Lap Imp for the 2k match. RL33 is good. N570 has been even better. 300s 5-10 off.

 

[alphapygmy]

We have been working with the 338 Lap Imp for the 2k match. RL33 is good. N570 has been even better.

VV powders are pretty scarce even in good times around here- central Idaho.

 

[Alex Wheeler]

It was hard to get for me too, long back order. It out shot 33 regardless.

 

[geralton4]

I've found ADI2225/Rutumbo to work very well in my rifle, low ES and SD's with a 91.5grn charge weight pushing Berger 300otm. I have also completed burn rate testing using the Thales ADI method. With out double checking my field notes, I believe it was as low as .5 fps or so per degree C of temperature span.