Daniel Defense URG Complete Upper Receiver, DDM4 300 S, 300 Blackout, 10.3", Black The Daniel Defense DDM4 300 S Upper Receiver Group puts a 10.3 inch cold hammer forged 300 Blackout barrel on a Mil-Spec upper. It uses standard 5.56 bolts and magazines, yet delivers .30 caliber bullets with more muzzle energy than comparable 5.56 setups, and 300 Blackout runs well both supersonic and subsonic. This is part number 23-088-19020-047, finished in black, supplied as a complete upper receiver group with the bolt carrier group and GRIP-N-RIP charging handle. A compact 300 Blackout upper with a 9 inch quad rail, built for suppressed and short-range work. 10.3 Inch 300 Blackout Barrel 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 300 S barrel is a 10.3 inch S2W profile, Daniel Defense's heavier contour, with a 1:8 twist that stabilizes both light supersonic and heavy subsonic bullets. A pistol-length gas system with a pinned low profile gas block of hardened 4140 steel is matched to the short barrel. The Daniel Defense Flash Suppressor is 17-4 PH stainless steel with a salt bath nitride finish. DDM4 Rail 9.0 The DDM4 Rail 9.0 is CNC machined from 6061-T6 aluminum and Type III hard coat anodized. It free floats the barrel and offers picatinny rail on four sides, with Santoprene rail panels, heat resistant to 300 degrees F, where your hand rests. It gives you room for a light, laser and grip without making the upper long. 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. 300 Blackout uses the same bolt as 5.56, so standard AR-15 magazines work. 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. Mark your magazines so 300 Blackout and 5.56 ammunition are never mixed. 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: DDM4 300 S Upper Receiver Group Part Number: 23-088-19020-047 UPC: 815604015134 Caliber: 300 Blackout Barrel: 10.3 in., cold hammer forged CMV steel, chrome lined, S2W profile Twist Rate: 1:8 Gas System: Pistol length, pinned low profile gas block Muzzle Device: Daniel Defense Flash Suppressor Handguard: DDM4 Rail 9.0 picatinny quad rail Sights: Sold separately Finish: Black, Type III hard coat anodized Weight: 3.65 lb Included: Upper receiver, barrel, handguard, bolt carrier group, charging handle Lower Receiver: Not included Frequently Asked Questions Can I use 5.56 magazines? Yes. 300 Blackout uses standard AR-15 magazines and the standard bolt. 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 twist rate does it have? 1:8. 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 DDM4 300 S Upper Receiver Group from BattleHawk Armory for a compact 300 Blackout build.