The Ruger AR-556 is an affordable" American-made modern sporting rifle with the rugged reliability that you have come to expect from Ruger. This model ships with a 10-round magazine for consumers in those states which limit magazine capacity. Lower receiver is fitted with Magpul MOE grip and MOE SL collapsible buttstock on a Mil-Spec buffer tube. Handguard is free-floated for accuracy and the slim" 15" length provides enhanced ergonomics. Bolt is mil-spec 9310 and is machined and shot peened for strength and durability. The Ruger Elite 452 AR-Trigger is a two-stage trigger that offers a smooth" crisp" 4.5 pound trigger pull. It features a full-strength hammer spring for consistent primer ignition and a lightweight hammer that enables a faster lock time for improved accuracy. Magpul M-LOK accessory attachment slots along the 3:00" 6:00 and 9:00 positions with additional slots on the angled faces near the muzzle. Ruger muzzle brake is a radial port design that significantly reduces felt recoil and muzzle movement. The threaded barrel allows for standard muzzle accessories to be installed. Cold hammer-forged 4140 chrome-moly steel barrel with ultra-precise rifling provides exceptional accuracy" longevity and easy cleaning. The 1:8" twist rate stabilizes bullets from 35 to 77 grains" and the 5.56 NATO chamber allows the use of both 5.56 NATO and .223 Rem. ammunition. M4 feed ramps provide improved reliability" and the matte black nitrided finish provides corrosion resistance. Made from aerospace-grade 7075-T6 aluminum forging" the flat top upper receiver includes a forward assist" dust cover and brass deflector" and is Type III hard-coat anodized for maximum durability. Bolt carrier and gas key have chrome-plated inside diameters to provide exceptional resistance to hot gases. The gas key is staked so that it will not loosen after extensive firing. Rifle-length gas system provides smoother operation and reduces felt recoil. This model ships with a 10-round magazine for consumers in those states which limit magazine capacity.