I use H1000 in my 243, 270,270wsm and 300 win. Its awesome, even better velocity than Reloader I did switch back to RL22 in my 300 win because I lucked into a load that shoots great. In my 270 I shoot 64 gr H1000 over a Barnes 130 Triple shock at 3100fps, in my 270wsm I shoot 70gr H1000 over a Barnes 140gr triple shock at 3240fps. In my 243 the velocity is not great 2950, but accuracy out of 100gr Sierra's is very good. Deffinately try some in your big game rifles.