I worked at an Army Reserve maintenance shop & one day I was handed an AKMS & told to render it inoperable by cutting a gap in the chamber (used air gouger) & then welding the bolt carrier to the front trunion. It was returned to the unit where it was added to the property book by serial number.
IIRC during OEF 1 a unit had to get a G.O. to sign off on their adding a full auto weapon to their museum & again it went on the unit property book by serial number before they rotated out of theater. I had to cut up a brand new Krinkov, enough to make grown men cry.
Some O-6 got busted in Iraq trying to smuggle out six AKMSs on a C-130, it helps not to get greedy.