I have the 300 Blk. process and load Down well. But I have never had this much trouble with a batch of 223 brass It is jinxed. they even check OK in Wilson case gauge
I recieved some Mixed brass 223 reloads that had problems. I got them for making 300 Blackout. At first I tried saving them by collet pulling and resizing to 223 small base die without decaping pin. then reassemble. Same Issue as before 1 out of 10 would jam in the chamber VERY tight. I'm Giving up. 300 blackout it will be.