“Three soldiers of the 1st Cavalry Division Aircraft captured during a cigarette break after returning from a mission. *Note the unusual Colt Commando Model 639 (?) With 11.5 inch barrel of the first soldier. Bravo Fire Support Base, Republic of Vietnam, Saturday, July 11, 1970”
~ Vietnam War
*The caption was with the image when I found it. I’ll have to research the weapon mentioned myself.