FFS....you guys are such experts...
The AR-15 is based on the 7.62 mm AR-10, designed by Eugene Stoner, Robert Fremont, and L. James Sullivan of the Fairchild ArmaLite corporation.[9] The AR-15 was developed as a lighter, 5.56 mm version of the AR-10. The "AR" in AR-15 comes from the ArmaLite name. ArmaLite's AR-1, AR-5, and some subsequent models were bolt action rifles, the AR-7 a semiautomatic survival rifle and there are shotguns and pistols whose model numbers include the "AR" prefix.[9]
ArmaLite sold its rights to the AR-10 and AR-15 to Colt in 1959. After a tour by Colt of the Far East, the first sale of AR-15s was made to Malaysia on September 30, 1959, with Colt's manufacture of their first 300 AR-15s in December 1959.[10] Colt marketed the AR-15 rifle to various military services around the world, including the U.S. Navy, Air Force, Army, and Marine Corps. The AR-15 was eventually adopted by the United States military under the designation M16.