Hi. I've been reloading for about a month now and I am really enjoying it. I have reloaded for my 308, my 7-08, and now for my .223 Remington. Can you guys tell me if I need to crimp the cases? I have read that it should be done for pumps, but have been told by a friend it is not necessary. I put 5 rounds in a magazine tonight, un-crimped and they fed fine. Am I asking for trouble?