1. It is illegal to ship ammo, i think he would know that and not just send ammo across country to someone you dont know.Why? Long guns are hard to disguise as far as length and weight. Just about any PO employee ought to figure out what it is. Maybe one of the higher ups who likes guns and is a thief and slip it under a coat and leave for the night. Maybe it was at a small PO that does not have cameras. Maybe it was the truck driver.
2. If he did, i am sure he knows how to tape a box up where it doesnt come open.
3. His FB plus the time on here.... i believe him without even talking to him.