The Colt CAR-15/XM-177 Colt Commando
The Colt CAR-15 (XM-177/Colt Commando) was a family of the AR-15 and M16 rifle–based firearms marketed by Colt in the late 1960s and early 1970s. Due to their compact size, the short-barreled Colt Commando and XM177 versions of this family continued to be issued to the U.S. military after the Vietnam War.
The CAR-15 name was an attempt to re-associate the AR-15 name with Colt, since the AR initially stood for ArmaLite Rifle, the original manufacturer. Colt later abandoned the CAR-15 concept, but continued to make variations, using the M16 brand for military-oriented models and the Colt AR-15 brand for law enforcement and civilian models. However, in present usage, CAR-15 is used as a generic name for carbine-length M16 and AR-15 variants from before the M4.
Specifically, "Colt Commando" currently refers to the ultrashort 11.5-inch (290 mm) barrel assault rifle of the Model 733 series. By comparison, the M4 Carbine has a 14.5-inch (370 mm) barrel, while the M16 assault rifle series has a 20-inch (510 mm) barrel.