Not all Win Mags. I'll give them a run for the money when fireforming is complete. This is fireforming, 1 grain under max load.We have that in the Sherman improved version of the 300 PRC. I guy in Montana took a bunch of game with it last year including moose. He can run the 156 Berger past 3500' but settled on a load in mid 3300's to gain some barrel life.
Its a lot faster than a WM!