At various times I carried a Thompson, CAR15, M79 blooper, M14, and M3 grease gun and of course an M16. I have to think as I may have missed one or two.
I was always looking for a good brush-chopper. The .45 cals excelled in the role but were just too damned heavy even if you only carried a hundred rounds. I used to see trace round from the 5.56mm’s bounce off of and be deflected by the undergrowth.
I finally got an M14 and hallelujah!
In retirement I love my M-14A. Originally qualified on the M-14 in 1969.
So comfortable to shoot; sometimes I have to drop the magazine so I won’t waste ammo enjoying that barely noticeable recoil.
Back to VN, one crewchief had an M79 made into a pistol which he wore around his neck. That was so long ago.