Advanced Armament AR-15 AAC 300 Blackout 16" Upper Receiver Assembly KAC URX II

Advanced Armament Co. AR-15 Flat-Top Upper Assembly 300 Blackout (7.62x35mm) 1:7" Twist 16" Barrel with KAC URX II Modular Free Float Quad Rail Handguard with Integral Front Sight , Blackout Flash Hider   The Advanced Armament Complete Upper Receiver Assembly in 300 AAC Blackout is a complete, pin-on replacement for your standard AR-15 lower receiver. The 4150 Chrome Moly Vanadium Steel Barrel comes with a 1 in 7" twist, M4 feed ramps, low profile steel gas block and protective Black Nitride finish inside and out for durability and corrosion resistance. The barrel's muzzle is threaded with a 5/8"-24 pitch for easy attachment of a sound suppressor, and is topped off with an effective AAC 51-T Blackout Flash Hider.  The Upper features a forged M4-Style Flat-Top Receiver onto which a Knight's Armament Free Floating URX II Modular Quad Rail Handguard with Integral flip up front sight is attached. The URX II creates a full length top rail when matched with the flat-top upper. A Full Auto Bolt Carrier with internal chrome lining houses the Carpenter 158 Steel Bolt, and is heat treated with a properly staked gas key. This 300 Blackout Upper employs the versatile Carbine Length Gas System, making it suitable for use with Subsonic or Supersonic loads, either Suppressed or Unsuppressed. However, subsonic ammunition may not always cycle reliably under adverse conditions without a sound suppressor attached. Specs: Upper Receiver: A3 Flat-Top Barrel Length: 16" Barrel Contour: Medium Barrel Material: 4150 Chrome Moly Vanadium Steel Muzzle Thread Pattern: 5/8"-24 Chrome Lined: No Barrel Finish: Black Nitride/Melonite Twist Rate: 1 in 7" Chamber: 300 AAC Blackout (7.62x35mm) M4 Feed Ramps: Yes Bolt Carrier: Mil-Spec Muzzle Device: AAC 51-T Blackout Flash Hider Gas System Length: Carbine Gas Block Diameter: 0.750" Handguard: Knight's Armament URX II Modular Quad Rail, Free Float Sights: Integral Front Flip Up Sight  Suitable for use with Subsonic or Supersonic loads, either Suppressed or Unsuppressed Compatible with all standard AR-15 magazines, including Magpul Pmags (Not Included) Mfg. Part #: 101716