Aero Precision M4E1 300 BLK 10″ Quantum M-LOK Complete Upper


Fully Assembled and Warrantied by Aero Precision

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Aero Precision M4E1 300 BLK 10" Quantum M-LOK Complete Upper

Aero Precision M4E1 300 BLK 10" Quantum M-LOK Complete Upper is the most efficient way to assemble your own semi-custom firearm; fully assembled and warrantied by Aero Precision.  This complete upper features an M4E1 Upper Receiver, 9" Quantum M-LOK Handguard, a 10" 300 BLK barrel with a standard birdcage muzzle device, and finished in hard coat black anodize.

**NFA Rules May Apply
***Does not include Bolt Carrier Group or Charging Handle.

M4E1 Upper Receiver Features:

  • New enhanced forging that gives the upper receiver a "billet look"
  • M4 Feed ramps
  • .250 takedown pin holes
  • Includes port door and forward assist installed

Quantum Handguard Features:

  • 1pc Free Float Design
  • Removable 4-slot picatinny rail section for front sight
  • Built-in anti-rotational tabs
  • 7 mounting surfaces for MLOK accessories.
  • 1.78" ID fits most muzzle devices and 1.5" suppressors
  • Compatible with low profile gas blocks
  • Compatible with mil-spec AR15 upper receivers and barrels

10" 300 BLK Barrel Features:

  • Material:  Chrome Moly Vanadium
  • Finish: QPQ Corrosion-resistant finish both inside and out.
  • Gas System: Pistol Gas w/ .750 Journal
  • Other: M4 Extension | HP, and MPI Tested
  • Standard A2 flash hider


  • M4E1 Assembled Upper Receiver
  • M-LOK Quantum Handguard
  • 10" 300 BLK CMV Barrel
  • Low Profile Gas Block and Gas Tube
  • Product comes assembled
  • This complete upper does not include BCG or Charging Handle.
  • The muzzle brake that comes with this complete upper receiver is NOT pinned nor welded to this barrel.
SKU APAR640102M4
Manufacturer Aero Precision
Made in America Yes
Assembled Yes
Receiver M4E1; M4 Feed Ramps
Barrel 300 BLK; 10" w/ A2 Birdcage Flash Hider
Handguard Free Float; MLOK; Quantum; 9"
Platform AR15
Finish Black Anodize
Gas System Pistol; .750 Diameter

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Weight 60 oz
Dimensions 20 × 6 × 6 in
Barrel Length


Gas System


Gas Block Diameter



300 Blackout

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