It would be nice to know small or large primer and the cartridge (chambering and brass manufacturer) and load. Though the answer would be the same.

If you are loading near max then after six or right reloads of anything you may be getting loose pockets. Some brass is softer than others (I understand Alpha Manufacturing lasts better than others). Milder loads maybe a dozen reloads, but by then there may be other reasons. If you see blackening around the primer after you shoot the time is past. This summer I was playing with a hot load and ejected a primer and the pocket was way larger than the primers. First time I got to test the gas vents on my Savage. Tight bolt and when I did get it open the primer was missing and I found it in the magazine A real eye opener! When I checked the earlier rounds of that batch I had two warning "blackenings" around the primers of fired cases. That was on Brass that had been fired and reloaded only twice prior.

I use a Lee Auto-Prime hand-primer and when they start to feel easy to my arthritic, office worker's hands it is time to retire the brass.