There's a full set of data avaiable on www.lapua.com
for the Vihtavuori line, and they have several excellent powders for the 338LM. I've also used (and had excellent results with) Retumbo and H1000 in this round. It's sort of like a really big 308; very stable, easy to work with and it seems almost harder to come up with a bad load than it does a good one. Not at all fussy or tempermental, and I like that. Very easy cartridge to work with, and delivers exceptional accuracy with a wide array of components.