Is it in anyway due to lockup on a particular action?
Have a used UltraComp barrel. Put it on an SB2 action and used it. The release lever has some play when locked up. Shot this weekend with one box of M2 ball. M2 is lightly loaded mil spec 30-06. In this case, 1969 vintage. A little tarnished. No FTF. Some cases stuck. PITA. I was going through the 1x fired cases to pick one to coat with metal polish and chuck in the drill. I did this by putting the fired cases in the chamber and ejecting them again. Some whacked me in the eye. Those primers looked normal. Some stuck until I opened and closed the gun a few times. Those primers looked slightly flatter. Some need a cleaning rod to remove. Those primers were flattest of all, but within normal range IMHO. I assume that I should use the easiest to eject cases to coat with JB. Again, this is from the same box of factory ammo. I know, I know, try some other ammo. Maybe next weekend. Real accurate gun BTW.