So I am reloading some brass, that I bought new. It has been fired three times. I did the Redding neck die the first time reloading and a full size Redding die the second time. This time is the third time to resize them. I am noticing that a few very few are getting a divot a small divot in the shoulder. I have cleaned my dies everything is great there. I’m wondering what the problem is. Out of 150 cases I noticed this happen to about six cases. Is this a problem that can be fixed with annealing? Or is this something else? Any and all help greatly appreciated.