Good luck with that. I once had UPS insist that a disassembled bolt-action rifle was still a “firearm” even though it had no bolt and no trigger assembly.
Well, per the ATF, the receiver is a firearm, no other parts required. I have to use my FFL to purchase a receiver, but not for any other part of a gun.
But the ATF does not consider an inert grenade to be an explosive. However, it won’t make it onto an airplane.
My point was that I somewhat understood how military personnel might think of inert Claymores as nothing more than training aids, which to the military and ATF, is all that they are. My biggest worry with the inert BDU-45s (concrete filled 500 pound bombs) was dropping one on my toe.