I've only annealed one time for the brass I'm loading now and have not reused that same brass yet, but, I will most likely be annealing every time as a guy I know and trust does his every time and I don't believe it hurts it any. If I get in a bind and need a lot in a hurry I may forgo every time. Most of my shooting is getting ready for some sort of hunting animals so I want it as accurate as I can get it so I try to not leave anything to chance.