head separation
I have had head separation on some .308 military brass that I necked down to .243 and all that I experienced was a slight puff of gas on my cheek. No problems getting the case out, a ,270 bore brush pushed in slightly past the case then retracted pulled it out with no problems. I have been told that the military brass is slightly thicker than the civilian .308.I have also had head separations on civilian brass- no problems. I should mention that I was using a Remington 700 action with a 26 inch barrel (not remington) and I suspect it had head space problems plus the brass that malfunctioned had been full length resized many times and the loads were slightly below max loads.