KNIGHT'S ARMAMENT SR-15 KS-1 5.56 NATO ASSEMBLED UPPER RECEIVER The KS-1 features a 13.7" heavy profile ball-mill dimpled cold hammer forged barrel. This carbine allows a small, high efficiency suppressor to be attached and still maintain an overall length similar to a 10.3" barrel with a standard suppressor, but with significantly higher muzzle velocity. The heavy profile barrel resist heat-induced shift, maintaining point of impact throughout long-duration use. Ball mill dimpling aids in weight reduction while reducing heat-related shift effect that can be seen with traditional fluting. SPECS Barrel: 13.7", cold hammer forged, Mfg: Knights Armament