Hugh, thanks for the clarification of the time to log the gun. My FFL has told me 24 hours in the past.
Steven, I don't think I suggested bending the rules "and then it's legal." I was asking if making a repair before returning to the seller would be within the regs. That's far, far different than bending the rules. Your response illustrates one of the problems on this and other boards, and that is the drawing of false conclusions and inferences, and taking arguments to extremes. Remember, this all started with an FFL who did not disclose in advance that he would not accept a gun from an unlicensed seller, even though it is perfectly legal to do so. His failure to disclose was not illegal, but it was bad business. He can run his business any way he wants, and we can use a different FFL. Simple.
