My Daughter and I decided to load some 7mm Rem Mag Ammo and go to the range. We took brand new Winchester brass , cci Lr mag primers and 57 grains H4831 behind a btsp 175 gr projectile and we fired about 4 shots and quit ! The gun is a beautiful custom mauser , the rounds chambered well and when we fired the bolt was tough to raise and very tough to bring back to the open position . I had to tap the bolt back with a wooden mallet . A couple of the primers blew out and the case heads are flattened and primers cratered , thats when we stopped shooting. I happened to have a few factory rounds and we tried those , no sticky boltor other problems. So my question is , did I use too much powder ? . My load data said starting load at 55gr and max load at 58 gr Just glad we had no Kaboom!!.your opinions appreciated.................LOUD