. "AR-15"@en . . "2270.0"^^ . . . . . "The AR-15 is a lightweight, intermediate cartridge magazine-fed, air-cooled Armalite Rifle with a rotating lock bolt, actuated by a piston within the bolt carrier or by conventional long/short stroke piston operation. It has been produced in many different versions, including numerous semi-automatic and select fire variants."@en . . .