I walk into ups ground hub with the ffl of the buyer in my hand (one in the box also) and ship shotguns often. Shipped one in December and one goes out this Friday. Shotgun is broken down and I let them know it’s in pieces with no ammo if they ask. Probably shipped 6 now over last 18 months. You can’t do this at a UPS store! If they ask for ffl,hand them the one in your hand(buyers who the gun actually belongs too since he paid for it already) never had much problem. I guess if we were talking mailing your own gun to a shop, have the shops ffl in your hand and do the same thing. Now obviously they won’t mail it back to you, must get mailed to FFL.