M4E1 Enhanced 10.5" 5.56 Complete Upper Receiver w/ Pinned FSB

Aero Precision M4E1 10.5" 5.56 Complete Upper Receiver w/ Pinned FSB

M4E1 Enhanced 10.5" 5.56 Complete Upper Receiver w/ Pinned FSB Product Sku: APPG600211P3

This Complete Upper includes our Gen 2 Enhanced Handguard! Key features include the addition of quick disconnect sling sockets, enhanced milling design for grip and visual appeal and a new profile for the picatinny top rail.


  • M4E1 Enhanced Assembled Upper Receiver
  • Enhanced Handguard of choice
  • 10.5" 5.56 Carbine Length CMV Barrel
  • Pinned FSB and Carbine Length Gas Tube
  • Product comes assembled
  • This complete upper does not include BCG or Charging Handle. These products may be selected as add-ons under the Finish Your Build tab
  • The muzzle brake that comes with this complete upper receiver is NOT pinned nor welded to this barrel. Per the National Firearms Act, the muzzle brake MUST be pinned and welded to achieve the necessary 16" as defined by the ATF for a rifle build.

M4E1 Upper Features:

  • Forged from 7075 T6 aluminum
  • Precision machined to M4E1 specs
  • M4 feedramps
  • Matte black hard coat anodized Mil 8625 Type 3 Class 2
  • Laser engraved T-marks
  • Comes assembled, with port door and forward assist installed
  • Accepts standard AR15/M16 components
  • Handguard mounting platform is forged into the receiver
  • Works with Aero Precision handguards but also fits most BAR-system handguards
  • Barrel nut and wrench are included

Gen 2 Enhanced Handguard Features:

  • 1pc free float design
  • Built in anti-rotation tabs
  • Scalloped rails
  • Continuous top rail
  • 1.78" inside diameter fits most muzzle devices and 1.5" suppressors
  • Compatible with low profile gas blocks
  • Gen 2 Feature - Quick disconnect sling socket at the 3, 6 and 9 o’clock positions
  • Gen 2 Feature - Additional milling along flats to aid with gripping and add visual appeal
  • Gen 2 Feature - New profile for the continuous picatinny top rail

10.5" Barrel w/ Pinned FSB Features:

  • 5.56 Nato, 10.5" carbine gas, 1/7 twist, 4150 CrMoV, with F marked FSB taper pin
  • .750 gas block journal
  • Carbine gas system
  • M4 Feed Ramp Extension
  • HP and MPI tested
  • Weight: 34 oz
  • Front sight block comes stripped, no sight post or sling swivel
  • Standard A2 flash hider
Made In America? Yes
Platform AR15
Series M4E1
Caliber 5.56 NATO
Barrel Length 10.5"
Weight(s) KeyMod: 49.84 oz / M-LOK: 49.84 oz / Quad Rail: 51.44 oz
Other No

Customer Reviews

4 Item(s)

No regrets Review by Benjamin
I couldn't ask for anything better. I bought this upper over a year ago and I've shot good ammo and cheap ammo from it. It eats up any type of ammo I have put into it. It has been very reliable. (Posted on 5/24/2018)
Great upper! Great price! Review by Miguel
First off... Thank you Aero_ Precision for the 10% military discount.
The upper is great, it fits great on my build lower receiver. Great shooting and accuracy. I highly recommend this upper for anyone building a short-length AR-15. (Posted on 2/23/2016)
Great product Review by David
I got my upper when it went on sale. What a great deal and the quality is top notch. Can't wait for my lower to get here in a few days. I will be getting another in 300 black out as soon as this build is complete. A++ (Posted on 11/13/2015)
Great value! Review by Will
For the money you can't beat it! (Posted on 9/20/2015)

4 Item(s)

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