In order to log the firearm into the A&D log, a smart FFL will verify the make/ model/ and serial number by taking the info off the firearm. Sloppy FFL's will just use the invoice, which could contain transposed serial numbers, etc. Another reason could be to catch shipping damage and get notification to the customer so a timely claim can be filed.
All correct. Another reason is that we often get guns shipped in where the customer didn't bother to tell us it was coming. We have to open it up to get contact information. The stupidest thing is that most of the time, they aren't even a regular customer, we just happen to be the closest dealer. I gave up asking them "would you buy something on line and have it shipped to a neighbor down the street without telling them that it was coming?".
