This DoubleStar AR-15 Upper Receiver Assembly in 300 AAC Blackout is a pin-on, ready-to-shoot top end for use with any legally registered SBR or dedicated pistol AR-15 lower receiver. The Mil-Spec 7.5” 4140 steel black nitride coated barrel comes equipped with 1 in 8" twist rifling, M4 feed ramps, and a DoubleStar picatinny rail gas block. The muzzle is threaded with a 5/8"-24 pitch for easy installation of a silencer, and is topped off with an effective A2 flash hider.
The upper features a hard coat anodized A3 flat-top receiver with a DoubleStar pistol length free-floating handguard, T-Marks, forward assist, and dust cover. The The DoubleStar Upper includes a standard AR-15 semi-auto bolt carrier, properly staked gas key with MPI bolt assembly.
This 7.5" 300 Blackout upper utilizes a pistol length gas system and is compatible with most subsonic and supersonic ammunition, with or without a sound suppressor in place. However, some subsonic ammunition may not always cycle reliably under adverse conditions or in a severely fouled firearm without a sound suppressor attached to provide extra backpressure.
Compatible w/standard AR-15 magazines, including Magpul Pmags (Not Included)
An “AR-15 Pistol” upper assembly has a barrel less than 16” in length. Pistol uppers are only for use on AR-15 pistol lowers and legal Short-Barreled Rifles. Other configurations may violate Federal law.
Installation of AR-15 upper assemblies with certain features including, but not limited to: flash hiders, bayonet lugs, and threaded muzzles may violate state and/or local laws.