H-414 is the best powder I have used in the 300 wsm with the 150 grain bullet. I have pushed it well over 3400 fps. My best accuracy load is around 3380 fps. Never tried it with heavy bullets. This powder may be to fast for best results with heavy bullets. Something around re-19 burn rate may work well for the heavy bullets.
I have used it in my son in laws and a 300 saum got the best vel. and accuracy with h-414. I feel that size case and bullet deph it is the best choice.
mike