Actually been a LONG time since I've shot any of those 50 calibers. I sold one of them a while back to help finance building the garage. And one of the remaining ones, I've never shot at all since I bought it. To be perfectly honest, I just might not ever shoot it.
Matter of fact, I was searching for something else, and found a Sig 556 rifle that I had completely forgotten I bought. I'm sure I've never fired that one neither. Wonder what else I've got laying around that I've forgotten about?