The KAC SR-15 is a AR variant carbine manufactured by Knight’s Armament Company (KAC). It is a semi-automatic rifle chambered for the 5.56×45mm NATO cartridge.
The SR-15 is a lightweight, magazine-fed, gas-operated, air-cooled, and shoulder-fired carbine. It features a 16 inch chrome-lined, ball milled, lightened barrel, and uses a mid-length gas system. Like the AR-15, it features an inline gas piston system which operates on expanding gas, using the pressure generated by the gas inside the hollowed-out bolt carrier to cycle the weapon. It features the KAC improved E3 bolt and barrel extension for greater parts life, and the improved bolt carrier (termed “Carbon Cutter”) which is more resistant to fouling in adverse conditions. The SR-16 also features a pressure reduction buffer to reduce vertical recoil, a two stage match trigger, ambidextrous controls (magazine release, bolt release safety switches), and a CTR style collapsible stock. It also comes with the URX rail (Upper Receiving Free Floating Rail System).