Originally Posted by mitchntx
...The only time the SN will be run through "the system" is if you commit a crime,...
Not necessarily. There may be other circumstances in which the serial number might be checked. And in many ways the practical concern is that if you are found with a stolen gun, even if it's absolutely clear that you came by it honestly and innocently, the gun will be taken from you to be returned to the rightful owner; and you will be out the money you paid for it.