The sizing and firing process is definite the culprit, I have cases that have 12 fairly hot loads thru them that have not been annealed, no loose primers in them. I also have rimmed brass that has only ever been fireformed and never sized again, that has 200+ rounds on it. Early on in learning about reloading, I had brass that would start a separation ring after about 5-6 loads, could just feel it starting with a paperclip, some changes to the sizing setup took that up to 10+, with belted cases. Lately, I've been using a bushing/bump die for those I can get it for. and a separate neck expander for those that I can't get the bushing die for. No idea what that will change, or not change for me. Trying to do bare minimum brass work on them anyway. Need to give that a year or two to see the results. I have a pile of brass that I could anneal and use again, but, haven't felt the need to do it, yet.
