Just fired my 1920's Bockbuchesflinte rifle barrel today for the first time, The BBF's caliber is 7x57R. I used Hornady 162 grain,balistic tip ammo and experienced some difficulty opening the action at times,not ALOT but noticably more force needed on the top lever than when shooting the shot barrel(16 ga.) do you guys know if these Hornady rounds are hotter than the Prvi Partisan or Sellier and Bellot? Any experience or info on these different makers 7x57R would be much appreciated! I chose this maker becouse there bullet wieght was more than the other two's at 139gr. and my BBF is marked on the chamber specifying 12 grams which is in the high 180's or 190 gr.,so I was trying to get closer to the wieght the sights were set up for. I just dont know about powder charge on these rounds! Dont want to shoot her loose! How do these rounds charge compare with how they loaded rounds pre war?? THANKS for any and all info! Kevin.