MPN: APAR640221M4 / APAR640221Q4


  • Caliber: .300 Blackout
  • Finish: Type III Class 2 Hardcoat Anodized
  • Upper Receiver: Aero Precision M4E1 Enhanced Upper Receiver - 7075-T6 Aluminum
  • Handguard: 9.3-Inch Enhanced Handguard
  • M4 Feed Ramps: Yes
  • Muzzle Device: A2 Flash Hider
  • Barrel: 10" 1:7 QPQ Coated 4150 Chrome Moly Vanadium
  • Muzzle Thread Pattern: 5/8"-24
  • Gas Block: Aero .750" Low-Profile Gas Block
  • Gas Tube: Pistol-Length Gas Tube
  • Bolt Carrier Group: Not Included
  • Charging Handle: Not Included
  • HP and MPI Tested

*This upper assembly does not come with Bolt Carrier Group and Charging Handle

*This upper receiver assembly has a barrel that is shorter than 16". This upper is only for use on AR pistol lower receivers and NFA registered Short-Barreled Rifle (SBR) lower receivers. All NFA laws apply!


  • Weight: ~2.73 lbs.
  • Length: ~18.5"


  • AR-15 lower receiver


  • 1x Aero Precision M4E1 10" 300 Blackout Enhanced Complete Upper Assembly


300 Blackout is the go-to caliber for SpecOps savvy individuals. If you want to build a hunting, close-quarter-combat, or home defense rifle that is capable, manoeuvrable, and deadly, the Aero Precision M4E1 Enhanced 10” .300 Blackout Complete Upper Receiver is for you. Capable of firing the .300 blackout, which has excellent damage ratings, pair that with subsonic rounds and a suppressor. You’ve got an adept rifle with minimal recoil and the slightest sound. These reasons make it favored by SWAT and other SpecOps units.

Short, Accurate, and Powerful

Despite having a 10’’ barrel, it is highly accurate at up to 480 meters. This means it can be used for hunting, target practice, CQB, and home defense. The M4 feed ramps aid in a reliable chambering of the rounds, reducing the chances of a misfire to a minimum, and a forward assist is also installed to help.

The barrel being high-pressure tested and magnetic particle inspected to ensure quality means that it has been tested for minor fractures, cracks, or imperfections after firing a proof round loaded to a higher pressure than a standard .300 BLK round. This ensures that you have a barrel of impressive quality and reliability.

Reliable, Versatile, and Beautiful

The pistol-length gas tube is perfectly suited for the subsonic rounds used in the .300 Blackout rifle. As the amount of propellant used in these rounds is less, the pistol-length gas tube delivers enough back pressure to push the bolt back and chamber a new round. The barrel is made of CMV steel. This ensures you have a stronger, heat and corrosion-resistant steel, so your rifle lasts the test of time.

Most muzzle devices and suppressors can be fit inside the 1.78” inside diameter handguard, ensuring you have a variety of muzzle attachments to choose from as per your preference. The barrel comes with a factory-fitted A2 flash hider.

The Gen-2 enhanced handguard provides quick disconnect sling sockets at three positions. This enhanced handguard has additional milling and a new visually appealing design.

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  • This Item: Aero Precision M4E1 10" 300 Blackout Enhanced Complete Upper Assembly
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    MSRP: $489.99
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