The full name of the gun is Colt AR-15 Commando XM177 Assault Carbine/Submachine. The gun was developed by Colt specifically for the Vietnam War and for the conditions that the special army forces would encounter in the jungle. The Commando was contracted over 2,800 times in for the US army in 1966. but was later substituted by the Colt Model 629 and Model 649 which were actually based on the CAR-15. The newer weapons were acquired over 500 times by the army since 1967. onwards. The Commando was still used in combat in South America and in the Yom Kipper War. The Commando was made by Colt in response for the army's desire for a shorter-barreled M16-like rifle and Model 607 SMGs in 1966. The Commando Model 609 had a front assist while the Model 610 did not. The Model 610B had a four position selector but it was not used by the army. The Model 629 and Model 649 were different from the Model 609 and 610 only by the longer barrel, which suppressed noise and made place for a grenade launcher. The Model 629 had forward assist but the Model 649 did not.