The "gun" as in action or part thereof that makes it a gun has to be received and kept at an FFL holder unless assigned to an individual that has passed a background check as in 4473---period. He has to work out of the registered address of the FFL. If a gun is left for "gunsmithing work" it can be returned to the owner without a background check IF it is returned within a 24 hour period----period. That is ATF regulation. You receive the gun it has to be at an FFL registered address and held at that address until it is signed for and a 4473 is completed and the gun is transferred to a person that has passed a background check. The ONLY way for a person to ship to another person without going through an FFL is if the firearm is being held for the owner---say a hunting trip. The person can ship the firearm to another address in THIER name and then ship it back to their home address after the event. Places like Sportsman Warehouse have each address listed ( and approved) as addresses under and listed on their FFL. In some cases it is a different license all together because it has been considered manufacturing not gunsmithing work. It seems silly but we, as in AGT, cannot even put a scope on a rifle and sell it as a package because that is considered "manufacturing." If the gun is purchased and then the scope is purchased and then we install the scope then that is gunsmithing and is ok. If the gun comes from a manufacturer as a package, with a scope installed, then that is ok to sell.In any event if the gun is dropped off at the shop, and it takes more than 24 hrs to attach the scope, the gun goes into the A&D book and the person has to fill out a 4473 to get their own gun back. That is why we have to list all the guns we take in as consignment sales. It doesn't make any sense but it doesn't have to, it's the government. They don't do things to make sense or to make the business any easier ( even though that is always a stated case) they do things to make it easier for them to penalize, fine, prosecute, and revoke. They have to justify their jobs somehow.