I have been messing with some brass that I know is on it’s last loading. I have a bunch more of it prepped and ready to load but maybe 10% of them are coming out of the chamber with partial case head separation. Should I have quit using it the first time this happened to a single piece or is ok to run through the rest of of the lot before trashing it? It’s been fired 5 times, Nosler brass 280 AI. I am not pushing it that hard and the gun has a tight chamber.