In 1959, ArmaLite sold its rights to the AR-10 and AR-15 to Colt's Manufacturing Company due to financial difficulties, and limitations in terms of manpower and production capacity. After modifications (most notably, the charging handle was re-located from under the carrying handle like AR-10 to the rear of the receiver), the new redesigned rifle was subsequently adopted by the U.S. military as the M16 Rifle. Colt continued to use the AR-15 trademark for its line of semi-automatic-only rifles, which it marketed to civilian and law-enforcement customers as the Colt AR-15.