Advanced Armament Co (AAC) AR-15 Pistol A3 Flat-Top Upper Assembly 300 AAC Blackout 1 in 7" Twist 9" Barrel with KAC URX III Modular Free Float Quad Rail Handguard, Blackout Flash Hider
- Sierra Matchking Bullets 300 AAC Blackout (308 Diameter) 125... $38.49 - $176.99 Select Options
- Lee Pacesetter 3-Die Set 300 AAC Blackout... $34.99 Out of Stock, Backorder OK
- Lee Factory Crimp Die 300 AAC Blackout... $13.29 Available
- Lee Case Length Gage and Shellholder 300 AAC Blackout... $5.19 Available
- Geissele Super Semi Automatic Trigger AR-15, LR-308 Small Pin... $210.00 Out of Stock, Backorder OK
- Remington Reloading Brass 300 AAC Blackout Primed... $27.99 - $133.99 Select Options
- ACE Improved Pistol Receiver Extension Buffer Tube Assembly... $67.99 Available
- Remington Premier Match Ammunition 300 AAC Blackout 125 Grain... $31.49 Out of Stock, Backorder OK
- Magpul PMAG M2 MOE Magazine AR-15 223 Remington 30-Round... $12.30 - $13.25 Select Options
- Frankford Arsenal Flip-Top Ammo Box #505 17 Remington, 204... $2.99 Select Options
- Hornady Reloading Brass 300 AAC Blackout Box of 50... $36.99 Available
- Gorilla Ammunition 300 AAC Blackout 220 Grain Sierra MatchKing... $28.99 - $289.90 Select Options
- Hornady Reloading Brass 300 Whisper Box of 50... $37.49 Available
- Accuracy International Magazine Accuracy International Chassis... $82.99 Available
- Hornady Gas Checks 22 Caliber Box of 1000... $27.49 Available
- Wheeler Engineering Trigger Pull Gage... $21.99 Available
- Hornady Gas Checks 45 Caliber Box of 1000... $42.49 Available
- Hornady Gas Checks 30 Caliber Box of 1000... $32.99 Available
- RCBS AR Series Small Base 2-Die Set with Taper Crimp 300 AAC... $43.99 Available
- Forster Replacement Decapping Assembly 300 AAC Blackout... $11.99 Available
The upper features a forged M4-style flat-top receiver onto which a Knight's Armament free floating URX III Modular Rail System is rigidly attached. The URX III creates a full length top rail surface when matched with the flat-top upper to accommodate almost any desired sighting arrangement. This customizable handguard allows shooters to attach modular rail sections along its length only where needed for adding accessories, keeping the remainder of the handguard slim, smooth, and snag-free. The heat-treated, full auto bolt carrier is finished in a slick Nickel Boron coating, and comes equipped with a properly-staked gas key and Carpenter 158 steel 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.
- Upper Receiver: A3 Flat-Top
- Barrel Length: 9"
- 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
- Bolt Carrier: Mil-Spec, Nickel Boron Finish
- M4 Feed Ramps: Yes
- Muzzle Device: AAC 51-T Blackout Flash Hider
- Gas System Length: Pistol
- Gas Block Diameter: 0.750"
- Handguard: Knight's Armament URX III Modular Rail, Free Float
- Sights: None
- Suitable for use w/Subsonic or Supersonic loads, either Suppressed or Unsuppressed
- Compatible w/standard AR-15 magazines, including Magpul Pmags (Not Included)
Please Note: 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.
Please Note: 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.