I’ve been reloading for quite some time. Not a lot just enough to hunt and such. I have ran into a problem that I’ve never had before. I loaded some 300wsm. I left them a little long (over mag length) so I had to load them by hand. I attempted to shoot 6 rounds. None of them fired. The primer had what appeared to be good firing pin marks but not ignition. I used some older primers. About 3 years old. I thought that was my problem. I got home. Pulled all the bullets. Then I decided to see if the primers were good. I shot all six in my rifle with just the primer. No powder or bullet. They all fired. Any idea what it could have been?