Aero Precision M4E1 Threaded AR-15 Barreled Upper Receiver .300 BLK Pistol Length - ATLAS S-ONE - 16"

Manufactured by Aero Precision
SKU: APAR700305M14
MPN: APAR700305M14
Manufactured by Aero Precision
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This Aero Precision M4E1 Threaded upper receiver group comes completely assembled with 16” .300 Blackout barrel and a pistol length gas system to ensure reliable function. Forged from 7075-T6 aluminum, this upper receiver features a billet design at a much lower cost and looks great when paired with the M4E1 lower receiver. The ATLAS S-ONE free float handguard is made from the same material with the same hardcoat anodized finish and features a lightened profile with M-LOK slots for accessories. This .300 Blackout AR-15 barreled upper receiver assembly does not include a BCG or charging handle but does include the forward assist and dust cover. Build a high quality .300 BLK AR pistol today with the M4E1 upper receiver assembly.

  • M4E1 threaded upper receiver
  • Forged 7075-T6 aluminum
  • Assembled forward assist and dust cover
  • 15” ATLAS S-ONE M-LOK handguard
  • Hardcoat anodized
  • 16” .300 Blackout barrel
  • Machined from Chrome Moly Vanadium
  • Pistol length gas system
  • 1:7 twist rate
  • Threaded 5/8x24
  • A2 flash hider
  • Salt Bath Nitride finished
  • Does not include BCG or charging handle

The 16” barrel is machined from Chrome Moly Vanadium steel with a salt bath Nitride finish and a 1:7 twist rate for stabilizing heavier rounds. It is threaded 5/8x24 with an A2 style flash hider. High pressure tested and magnetic particle inspected ensure this barrel is accurate and reliable. This Aero Precision AR-15 barreled upper is a great choice for finishing an AR build.

Aero Precision takes some of the most state-of-the-art manufacturing techniques and equipment derived from their work in the aerospace industry and applies it to their products in the firearms industry. They have utilized their knowledge from years of building aircraft components to design and engineer AR-15 handguards, receiver sets, scope mounts, and more. They treat every product as if it were a precision flying machine and adhere to strict quality standards to ensure law enforcement, military, and civilian customers receive a product they can rely on.
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Barrel ContourMedium
Barrel Length16
Barrel Material4140 Chrome Moly Steel
BrandAero Precision
Caliber Gauge300 Blackout
Gas System LengthPistol
Gas System TypeDirect Impingement
Handguard15 in M-LOK Rail
Muzzle DeviceA2 Flash Hider
Twist Rate1:7
California Prop 65 warning

 WARNING: This product can expose you to chemicals, which are known to the State of California to cause Cancer and Reproductive Harm. For more information go to

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