Thread: Best .300WM Brass

The secret for longer life in magnum belted brass, is when it is brand new, never fired, to expend the neck to the next caliber up (8 mm for 30) and then neck size down back to original caliber till the bolt of your gun just close on your neck. Do your first fireforming with a normal load. And on the consecutive reloads just neck size your brass. Only full length size it when bolt become stiff but just enough so you just bump the shoulder back.
If you are not pushing the pressure to high, you should get 10 reloads out of your cases.