The Smith Wesson MP15 is an AR-style gas-operated semi-automatic rifle designed with military and police as well as personal use in mind. It is chambered in 5.56mm NATO.223 Remington 22 LR and 5.4539mm with an aluminum receiver with hard-coat black anodized finish and either melonite- or chrome-lined barrel. It features a integral trigger guard 6-position telescoping butt stock and adjustable sights. The MP15 is compatible with most standard AR-15 mil-spec components and accessories. Caliber 5.56 mm NATO - Action Gas Operated Semi Auto - Capacity 10 Rounds - Barrel Length 16 (40.64 cm) - Front Sight Adj. A2 Post - Overall Length 35.0 (88.90 cm) - Grip Polymer - Weight 6.8 lbs. (2948.35 g) - Barrel Material 4140 Steel - Upper Material 7075 T6 - Lower Material Aluminum - Finish Matte Black