If an Item is brought in for gunsmithing or repair and the owner waits while it is being repaired or if the gunsmith is able to return the firearm to the owner during the same business day, it is not necessary to log the Item into your A&D records. (ATF Ruling 77-1)
If the gunsmith has possession of the Item from one business day to another or longer, the Item must be recorded as an Acquisition and a Disposition in your A&D records. (ATF Ruling 77-1)
FFLGuard’s Best-In-Class practices recommend that you always log any firearm that is brought in and left by it’s owner for any reason or any amount of time. You cannot get a violation for logging it in. You can get a violation for forgetting to log it in.
You are not required to complete a 4473 when the item was brought in for the sole purpose of gunsmithing or repair and you’re returning the Item to the same person you received it from.