I have an XCR .375 RUM on the way and was woundering if any of you guys are shooting one?

What powders are best in this beast?

I'll be loading some 225gr and 270gr Hornadys as well.

I had best luck with Norma 15 (VERY similar to RL22) and VV N560 with heavy bullets (270+grs). I have not tested the 225 HDY, but I use the Speer 235 with vv N160 for 'plinking'

My favorite hunting load: 270grs Barnes TSX, 99grs VV N560 or 99grs Norma15, Federal 215 primer. This load is ca. 1 grs under max in my custom Mauser - prescision is superb.

RL 22 is a very good powder for the 300 gr's
Imr 7828ssc and H4350,VV N560,N160 AND N165.

My load is 99gr of RL 22 and the Barnes 300gr TSX.