Hi in my DTA SRS for my 338 LM i use Reloader 25. 90.2grns under the Berger 300grn Hybrids. There are many different powders out there for this round, Retumbo, H1000, RL25 and now RL33 seem to be the most popular. Always start 10% low and build up slowly. Dont forget just because one recipe...