I use combo NON TSA locks. Tell the counter clerk at checkin that you are checking a firearm. They will dispatch TSA to fetch you and the gun. They will take you to a small room to xray the case. If needed, they will ask you to open it for further inspection. Do not give them the combo. Once it is inspected, they check it and it is free from further inspection on that one way trip. It comes around the carousel.