I'm using a lyman tool to reem.
The press did the same thing to fc brass. I'm waiting to reload anything until I get the rcbs swager. Most of my brass is hornady 1x I got from someone who shot it from a bolt and didn't reload for 308
Idk if this helps but here are to diffent match cases. On the left hornady on the right nosler. Both 10
Hornady looks to have an insert or something compared to the nosler
Only thing I can possibley think of is ehat I said earlier of the cases being over reamed and when the primer ignited instead of shooting everything forward some came back out the primer pocket. I'll try to prime some un reamed case and hopefully it works out if not I'll be reporting back. Thanks for your time guys. I just don't know why with my match brass the primers won't go in