At my location there is a gentleman who builds .50 cal rifles for certain military units who ships these rifles through the airlines to overseas locations all the time. You certainly jumped through some hoops in order to get your authorization to purchase suppressors, so you should also know that you can ship weapons from a licensed dealer in your area to a licensed dealer to the area you are going to. Long guns can be disassembled and shipped in a less obvious hard sided lockable case.