I am working on my dads 300 win. It likes H4350 the best with 165 hornady sp's and the 180 grain tsx. I did not crimp the cases. Full length size them and trim when needed. I would stay away from Federal brass. Myself, I have had too many split cases in all calibers and do not use them for reloading. Make sure you seat them deep enough to fit in the magazine. I made that mistake I could have used them in a bolt gun but not the R1. Hope this helps.