Daniel Defense URG Complete Upper Receiver, MK18 RIS II, 5.56 NATO, 10.3", Black/FDE The Daniel Defense MK18 Upper Receiver Group carries the same RIS II picatinny quad rail that Daniel Defense supplies to USSOCOM, mounted over a 10.3 inch cold hammer forged barrel. That barrel length matches the MK18 uppers most commonly used for close quarters work, so you get a compact, fast-handling top end with a proven pedigree. This is part number 23-004-08013-011: a black upper receiver with a Flat Dark Earth RIS II rail. It comes as a complete upper receiver group with the bolt carrier group and GRIP-N-RIP charging handle. The USSOCOM-proven RIS II MK18 upper with a 10.3 inch barrel, ready to pin on. RIS II MK18 Rail The RIS II MK18 rail is CNC machined from 6061-T6 aluminum and Type III hard coat anodized, here in Flat Dark Earth. It uses a Bolt-Up System that was rigorously tested before USSOCOM fielded it, and the rail free floats the barrel while giving you picatinny mounting on four sides for lights, lasers and a forward grip. Santoprene rail panels, heat resistant to 300 degrees F, protect your hand where you hold the rail. 10.3 Inch Barrel and Carbine Gas Daniel Defense hammer forges its barrels in house from chrome moly vanadium steel. Cold hammer forging packs the steel tight around a mandrel, which gives long barrel life and consistent accuracy. Each barrel is chrome lined, Mil-Spec heavy phosphate coated and HP/MPI tested. The MK18 barrel is a 10.3 inch government profile with a 1:7 twist. Gas runs through a carbine-length system and a pinned low profile gas block machined from hardened 4140 steel. The 1/2x28 muzzle wears a Daniel Defense Flash Suppressor in 17-4 PH stainless steel with a salt bath nitride finish. Receiver, BCG and Charging Handle The upper receiver is Mil-Spec with indexing marks and M4 feed ramps, CNC machined from 7075-T6 aluminum and Type III hard coat anodized. The bolt carrier group is M16 profile, Mil-Spec MP tested and chrome lined, with a properly staked gas key. The GRIP-N-RIP charging handle has independent latches on both sides, so left- and right-handed shooters can run the rifle the same way. Sights are sold separately. Installation and Compatibility This upper receiver group fits any Mil-Spec AR-15 lower receiver. Install it with the two takedown pins, then function check before live fire. Because the barrel is 10.3 inches, putting this upper on a lower with a stock makes a short-barreled rifle under the NFA. Register the SBR first, or use it on a pistol lower where legal. Lower receiver, stock, magazine and optics are sold separately. An upper receiver is not the regulated part of an AR-15, so it can ship directly to you where state and local law allow. Browse more Daniel Defense firearms or see AR-15 rifles if you would rather buy a complete gun. Product Specifications Manufacturer: Daniel Defense Model: MK18 Upper Receiver Group Part Number: 23-004-08013-011 UPC: 852548002592 Caliber: 5.56mm NATO / .223 Remington Barrel: 10.3 in., cold hammer forged CMV steel, chrome lined, government profile Twist Rate: 1:7 Gas System: Carbine length, pinned low profile gas block Muzzle Device: Daniel Defense Flash Suppressor Handguard: Daniel Defense RIS II MK18 picatinny quad rail, FDE Sights: Sold separately Finish: Black receiver, Flat Dark Earth rail Weight: 3.5 lb Included: Upper receiver, barrel, handguard, bolt carrier group, charging handle Lower Receiver: Not included Frequently Asked Questions Is this an SBR? The upper alone is not. On a stocked lower the 10.3 inch barrel makes an SBR, which needs NFA registration first. What color is it? The upper receiver is black and the RIS II rail is Flat Dark Earth. Does it come with sights? No. Sights are sold separately. Does it include a bolt carrier group? Yes. An M16 profile, MP tested, chrome lined BCG is included, along with the charging handle. Is a lower receiver included? No. This is an upper only; it fits any Mil-Spec AR-15 lower. Do I need an FFL to buy it? No. An upper receiver is not a firearm under federal law, but check your state and local laws. Order the Daniel Defense MK18 Upper Receiver Group from BattleHawk Armory and build the compact AR you have been planning.