The Ruger AR-556 offers consumers an affordable, American-made modern sporting rifle with the rugged reliability they have come to expect from Ruger. The AR-556 is constructed from top-quality components, including forged 7075-T6 aluminum upper and lower receivers and a chrome-moly steel barrel with M4 feed ramp cuts. The 16.1-inch medium contour barrel is cold hammer-forged, providing ultra-precise rifling for exceptional accuracy, longevity and easy cleaning. The AR-556's carbine-length, flat-top, M4 design is fully configured with a six-position telescoping stock and heat-resistant glass-filled nylon hand guards for shooting comfort and durability. The Ruger Rapid Deploy folding rear sight provides windage adjustability and is a solid, reliable aiming system when coupled with the elevation-adjustable front sight. The rear sight can be folded out of the way to make room for optics. The chrome-plated bolt carrier inside diameter and chrome-plated gas key inside diameter provide exceptional resistance to hot gases. The gas key is staked so that it will not loosen after extensive firing. Standardized M4/AR components are utilized throughout, so the AR-556 can be customized easily. 30-round Magpul PMAG. 1 in 8" twist.