Short-stroke gas piston; 3 position gas regulator - Regular \ Extreme \ Suppressor use; Hammer-forged, chrome-lined, free-floating barrel, for enhanced accuracy & prolonged life cycle; Hard-anodized monolithic aluminum MIL-STD 1913 Rail; The rifle is equipped with a significantly efficient jump compensator for better shooter stability; MIL-STD 1913 accessory rails at the 3, 6 and 9 o'clock positions