DoubleStar AR-15 A3 Pistol Upper Receiver Assembly 300 AAC Blackout 9″ Barrel 1 in 8″ Twist Information
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 9” 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 9″ 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.
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.
|Cartridge||300 AAC Blackout (7.62x35mm)|
|Barrel Length||9 Inches|
|Barrel Finish||Black Salt Bath Nitride|
|Gas Block Diameter||0.75 Inches|
|Gas System Length||Pistol|
|M4 Feed Ramps||Yes|
|Upper Receiver Type||A3 Flat-Top|
|Barrel Material||4140 Chrome Moly Steel|
|Handguard||Pistol Length, 6061-T6 Aluminum, Free Floating|
|Bolt Carrier Assembly Included||Yes|
|Muzzle Device||A2 Flash Hider|
|Mil-Spec or Commercial||Commercial|
|Shipping Weight||3.675 Pounds|