During the Vietnam War, American soldiers encountered problems with their full-sized M14 and M16 rifles. Their size made it difficult to both carry and aim them in the jungles covering most of Vietnam. Because encounters with the enemy in this thick foliage often were short-range, quick firefights between small units, soldiers needed a weapon that could be quickly aimed and fired, rather than long-range accuracy. In 1966, to alleviate this problem, the U.S. Army purchased and issued Colt 609 Commando's (Army classification XM117E1) to front-line troops. Several problems were found with the carbine, including double feeds (also a problem with early M16's and aggravated by the shortened gas-porting system), loud report and bright muzzle flash (caused by the shortened barrel allowing more pro