AR-15 Rifle

An AR-15-style rifle is a lightweight semi-automatic rifle based on or similar to the Colt AR-15 design, which was originally a scaled-down derivative of the AR-10 design. The Colt AR-15 was created after ArmaLite sold the patent and trademarks to Colt's Manufacturing Company in 1959, and Colt began selling its own version with an improved semi-automatic design in 1964. After Colt's patents expired in 1977, many firearm manufacturers began producing copies of the rifle under various names, and the term "modern sporting rifle" was coined in 2009 to describe modular semi-automatic rifles including AR-15s.learn more on wikipedia