KNIGHT'S ARMAMENT SR-15 KS-4 5.56 NATO SEMI-AUTO RIFLE The KS-4 features a 16" cold hammer forged barrel. A 15" URX6 handguard fully protects the barrel and gas system, with ample mounting space for large night-vision devices in conjunction with high magnification primary optics, while leaving sufficient room for a suppressor. SPECS Barrel: 16", cold hammer forged, 1:7" twist, chrome lined Cartridge: 5.56 NATO Weight: 6.55 lbs. Length: 32.5" - 35.7" Mfg: Knights Armament