As a licensed FFL Dealer they keep track of the serial numbers for legal reasons. Not necessary for records on who they sold it to, but that they actual sold it. Like any other retail business you get stock in and you sell it. For tax purposes you will need to prove what all you have sold in a fiscal year, and since all guns of the same model are the same, they must keep track of the serial number to identify the firearm they have sold and which ones are in stock. Think of it as buying a TV from walmart, the tv you buy has a serial number that is stored in the bar code, this way at any time they can tell what is and isn't in the store, also at what time a specific tv was sold.
As a licensed FFL Dealer they keep track of the serial numbers for legal reasons. Not necessary for records on who they sold it to, but that they actual sold it. Like any other retail business you get stock in and you sell it. For tax purposes you will need to prove what all you have sold in a fiscal year, and since all guns of the same model are the same, they must keep track of the serial number to identify the firearm they have sold and which ones are in stock. Think of it as buying a TV from walmart, the tv you buy has a serial number that is stored in the bar code, this way at any time they can tell what is and isn't in the store, also at what time a specific tv was sold.