The AR-10 is an American 7.62 mm battle rifle developed by Eugene Stoner in the late 1950s at ArmaLite, then a division of the Fairchild Aircraft Corporation. When first introduced in 1956, the AR-10 used an innovative straight-line barrel/stock design with phenolic composite and forged alloy parts resulting in a small arm significantly easier to control in automatic fire and over 1 lb (0.45 kg) lighter than other infantry rifles of the day. Over its production life, the original AR-10 was built in relatively small numbers, with fewer than 10,000 rifles assembled.
In 1957, the basic AR-10 design was rescaled and substantially modified by ArmaLite to accommodate the .223 Remington cartridge, and given the designation AR-15. Developed by Colt Firearms, the AR-15 would eventually become the M16 rifle.