I recently inherited a remington gamemaster 760 in 30-06, early model 1950s era. Well, I was given some old ammo that looks to be from the 70s (peters 220 grain). I shot about 20 rounds of brand new remington green box thru it and it performed flawlessly. I decided to see if any of that old ammo was any good, so I shot a few rounds of it and afterwards I picked up the brass and the end near the primer was cracked or melted a bit. I figured I shouldn't shoot any more of this so I wouldn't damage the rifle.... is there any negative consequences that could occur from using this ammo? I am not really going to use it, I'm more curious than anything. I don't see the point in using unsafe ammo when a box if decent ammo is under $20.