How am I supposed to prove that the gun is mine? Should I carry a receipt with me at all times? What if I borrowed it from a friend?
Let's see. If you are not prohibited from carrying a gun, such as being a felon or a minor child not in the presence of his/her parent or guardian, then you are in lawful possession. Right? Hell, when I was 12 I was hunting with a 22 all over the woods behind the house. I often walked down the road with the rifle slung over my shoulder.