AR-15 - civilian rifle, produced in many different versions 
A light gas-dynamic rifle, air-cooled, magazine-powered, uses intermediate ammunition. Aluminum alloys and synthetic materials are widely used in its production

The AR-15 is based on the 7.62mm AR-10 rifle developed by Eugene Stoner. It was designed as a lighter version of this weapon in 5.56 mm caliber

In 1959, Armalite sold its rights to the AR-10 and AR-15 to Colt, which, after modifications, began selling it in 1964.

The rifle was adopted by the United States Armed Forces as the M16