I asked the same question when I bougtht my 270WSM, mine is a Ruger. Load for the cartridge not for the barrel. I have had excellent accuracy with 140 gr Nosler Accubonds and Hornady SST's sitting on top of 58.5 gr of I 4350, Federal lrm primers in WW brass. MOA groups at 100 yds and that was before the trigger and bedding were taken care of. H4831 and RE19 or 22 are also good powders. Your gun may like a different load though. The nice thing about the wsm's are that you can load them down to standard speeds and not suffer in the accuracy potential.