 Due to financial problems, and limitations in terms of manpower and production capacity, ArmaLite sold the ArmaLite Rifle-15, abbreviated AR-15 design and the AR-15 trademark along with the ArmaLite AR-10 to Colt's Manufacturing Company in 1959.Colt started selling the semi-automatic version of the M16 rifle as the Colt AR-15 in 1964.The first mass production version was the Colt AR-15 Sporter, in .223 Remington, with a 20-inch barrel and issued with 5-round magazines.