As an M1A shooter, I have had a "squib" load before. You won't hear anything, even when the primer goes off. It just sounds like a dud. I have never had that many bad primers... ever, and have loaded at least 5000 rounds. Pull the rest of your reloads and make sure they have powder. Then, if you want to, chamber a primed empty case and fire it. It'll just sound like a firecracker.

Also. I believe 46 grains of either 4895 is a little hot for the M1A. I load 42 grains and it is accurate. A 155 grain bullet according to Hornady, has a max charge of 42.9 (h4895) and 43.4 (IMR4895).