There were two GIs who stayed in one of our FDC hooches at B Battery near Da Nang. It was their job to go out on a Marine tank with a searchlight every night and watch the perimeter somewhere down the road. They never spoke to anyone and we didn't even know their names.
One day while they were sleeping in a jeep, our FDO, Lt. White, walked by and "lifted" one of their M-16s. He gave it to me for "safekeeping" as he did not want them to get into trouble with their CO -- just maybe give them a chewing out for allowing one of their rifles to get stolen. Days went by and they said nothing to anybody about their missing rifle. The next week, we noticed that they had two rifles again. I kept the extra rifle; just Lt. White and I knew about it.
There were two RTT men who also stayed in the other hooch. Jim and Tom were likable guys, though. One day in late December 1968, I could tell that something was bothering Jim. He told me that he had been on a riverboat and his M-16 accidentally fell overboard. He didn't like not having a weapon and he couldn't get one from B Battery legally, as his unit was in Dong Ha. With Lt. White's approval, I gave Jim the extra rifle. All around, the three of us felt better.