When I was in Army I was involved with M2s as well as the smaller weapons. The security on small arms ammo was tight. The 50cal ammo they didn’t worry about. Maybe a guy would boost a round for a souvenir but there weren’t many 50cal rifles 50+ years ago. First one I saw was made up out of a spotter gun off a 106 Ricky. I declined to my opportunity to shoot it because their was no recoil system. Three or four rounds and even the Rambo’s had enough.
Army towed abandoned vehicles into White Sands for targets. They would throw in some gasoline and role up windows. When these were hit they blew up in ball of flame. Overseas the 50APs would chew a block building to dust.