The Knight’s Armament Company SR-15 line represents the pinnacle of firearms based upon the Eugene Stoner designed operating system. The Mod 2’s 16” chrome lined, 5.56mm NATO barrel is manufactured to military specifications, and features a proprietary mid-length gas system that increases reliability and durability while also reducing felt recoil. An improved E3 round-lug bolt design both enhances function and increases bolt life far beyond the industry standard. The Mod 2 gas system minimizes the chances of gas leakage and ensures more consistent operation in harsh conditions. The new gas block is secured with a locking ring instead of taper pins, which increases barrel rigidity and eliminates the need to custom fit the gas block to the barrel. A URX 4 handguard with Keymod accessory mounting points for ancillary device attachments, increases cooling characteristics and reduces weight and bulk compared to standard M1913 rail attachment methods.