So I know that the general rule is 18 for a long gun, 21 for a handgun and ammunition, but there seems to be some gray area. Could you buy a handgun, and ammo, from a non-federally authorized dealer at the age of 18? Say at a gun show? Just wondering if that is possible. I know laws vary but state, I live in WI, but the law says that this is possible but I can't find out for sure. Any help would be appreciated.