In my VN time (1964-66), (1967-69) and part of 1971 I saw just about of every kind of handgun, even an old "hammer the hammer" H&R .22. I was an Army Aviator(rotary and starch wing). The army issued mainly M-10s of various -#s, round and square butt 4" .38 special. But had some Colt OPs and even Detective Specials in the arms room. The M15 was strictly a USAF issue, not to say some were not traded off to other service personnel. The .38 special had 2 particular advantages for aviators: 1. It could be fired right now with one hand (hand/arm in juries were common in both crashes and ejections). 2. It could fire the tiny flares that were issued-mainly by AF/Navy, but lots of Army pilots/aircrew got them. I carried about 20 of them all the time figuring that it would take a few to get attention. I preferred the big (37mm) infantry parachute or star flares if I could get them. For a while I carried a 1911a1 also. I got a Thompson 1928 from an AF guy in a poker game and carried that and 3 100 round drums for a while but they were really heavy, even with a load of 30 round stick mags it was cumbersome. Eventually I settled on a BHP and a Swedish K SMG (S&W made?). Both used 9mm and could pack a lot of that ammo. I was co located at Ubon AFB (flying JOV1As) with the AF guys, and the armorer there did an action job on my M10 that was so slick I could just barely believe it. Like an idiot I turned it in when I went back to Army commands. On my last tour I had a M10 that was marked "DCMP" on the back strap, later learned that it was diverted to the military from an order for the Washington Metro Police-I was smart enough to keep that one by then. As a useful weapon the handguns were more of a morale issue than a real weapon. However I felt better with one, particularly knowing if I could get to it I was never going to burn. An issue that was seldom talked about, but always in the back of your mind-aluminum burns at very high temp.