Re: AR .260 chews 'em up and spits 'em out...
I agree with everyone who mentioned overpresure.
Are the primers compromised on factory loads as well?
If you have a stoney point you could check to see where your lands are.
Can you post your loads including powder Bullet, weight, OAL and or BTO as well as the length to landsif you have it.
I aim to be the man my dog thinks I am.