Thread: Case head separation imminent

My suggestion is that the cases may not be as alike as you think. The manufacturer may be the same but unless you bought the whole 200 at the same time and of the same batch there could be some significant differences in case body brass hardness and structure. You could just be seeing the weaker cases failing first. This is exactly what you would expect. Check the inside of the surviving cases with a bent paper clip with the end bent and sharpened to a point to see if there is a groove is developing. You have not told us how you set your sizing die to eliminate excess head space. Ask any questions you may have, between us we all may learn something.
Regards Grandpamac.