Colt Model 639: MACVSOG's Vietnam Carbine
The Colt Model 639 is an export variant of the XM177E2, notable for its use by MACVSOG during the Vietnam War. It features an 11.5-inch barrel and a unique muzzle moderator designed to alter its sound signature. Due to ATF regulations classifying these moderators as suppressors, many were recalled, making the Model 639 exceptionally rare.









