Home Forums Reloading Big Game Rifles Need help on 338 Win Mag powder

I done a little research on powders for reloading the 338 Win Mag using 225gr bullets and two powders seem to be always at the top. They are H4350 and RL-19. I have H4350 on hand but have never used RL-19. I have heard that the Alliant powders can be sensitive to temp. I just want to know if anyone else has used Alliant RL-19 and done any testing to see if there is a large vel. change with temp. Any help is appreciated.

See the thread below on Re-19. Sounds like a winner in that cartridge.

yes, very good for 225 in .338 !!!

I've shot the same load at 4 degrees to 85 degrees. Velocity in 10 shot strings varied less than 30 fps. Doesn't appear to be too sensitive in my testing.
I have heard though, that they tend to be sensitive on the HIGH end i.e. don't work up a max load at 40 degrees then use it at 100

Both are good powders for the 338/225grs. Utah said it best, work up with high temps, it can be touchy (RL-19). RL-22 can push NP 225's at or close to 2,900 with good hunting accuracy. My gun uses 74.5 grs but some data can go to 77grs, ditto for load development with it as well.
John Barsness has probably forgotten more 338 loads than we'll ever see. Look him up.

I did much better with RL22 with both 225g and 250g bullets both for accuracy and velocity. Because of temperature tolerance I ultimately have been using H4831 with about a 50fps reduction in velocity from the Reloader powders but about the same accuracy.

rdd:
My load in the .338 mag. is 73 grs. of Rldr-22 and a 225 gr. North Fork. I'm at 2800 fps as I recall. Good accuracy and performance. Can't comment on temp. sensitivity - it's never been a concern for me. Try the North Fork's, I think you'll like 'em. Bear in Fairbanks

I use IMR-4350 or RL-22 with 225 gr in my .338 Tikka, and both work well. I have not used the rifle in super cold weather, but have at temps into the 90's. It likes loads at the max level, for best accuracy - well under MOA. The results have been good wnough that I see no need to experiment futher.

Thanks for all of the input. It sounds like it would be worth the time and money to get a lb. of RL-19 and work up some loads. I will be using Hornady 225gr, Barnes 225gr TSX and Nosler 225gr Accubond. If I can get 1" groups and 2850 fps I will be a happy camper.

Don't forget the Nosler 210 Partition. That bullet with RL19 was my go to load with the 338.

RL22 at 75grs was good with 225gr HSP and 200gr NAB and 73grs H4350 is scary accurate. I am now playing around with 210NP and 71-73grs H4350.

RL-19 for <210 grains; RL22 for >210 grains.

Norma MRP in place of RL22 if you can get it.

MM

I used H4831SC for all the bullet weights.

X2 I find this powder excellent accuracy and great speed, 2950fps with 78gr H4831 with a 225 partition.

The two other long time 338WM shooters I know use RL-22.I use N-560.