M4E1 Enhanced 14.5" 5.56 Mid-Length Complete Upper Receiver

Aero Precision 14.5" 5.56 Mid-Length Complete Uppers - Anodized Black

M4E1 Enhanced 14.5" 5.56 Mid-Length Complete Upper Receiver Product Sku: APPG600231P5

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
  • 14.5" 5.56 Mid-Length CMV Barrel
  • Low Profile Gas Block and Mid 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

14.5" 5.56 Mid-Length Barrel Features:

  • Chamber: 5.56
  • Length: 14.5"
  • Twist: 1 in 7
  • Threading: 1/2"x28
  • Material: Chrome Moly Vanadium
  • Finish: QPQ corrosion resistant finish both inside and out
  • Gas Block: .750
  • Gas Port: .0785
  • Gas System Length: Mid
  • Weight: 26oz
  • M4 Barrel Extension
  • HP and MPI Tested
Made In America? Yes
Platform AR15
Series M4E1
Caliber 5.56 NATO
Barrel Length 14.5"
Weight(s) KeyMod: 49.98 oz / M-LOK: 49.98 oz / Quad Rail: 52.38 oz
Other No

Customer Reviews

5 Item(s)

Update to previous review.... Review by PHIL
FINALLY, as summer's winding down and time has freed up, I was excited to get out and put the first rounds downrange w/ my m4e1. Discovered that the weapon system is deadlined due to improper short side head spacing (marring up casings and even complete separation of bullet from case when ejecting cartridge). Sub'd help desk ticket...very slow responses. I am a local customer and am still forced to deal with waiting on pre-paid shipping etc as they won't let me drop it off in person. To top it off, my teammate from Iraq will be in town tomorrow visiting and thus our plans to go shooting are ruined. I trust that eventually AP will resolve the issue and will update review at that time appropriately. Wishing now that I had made a different decision w/ regard to sourcing given the great local manufacturers in WA state. (Posted on 8/31/2017)
Expect a small break in period Review by Nicholas
I ordered this to toss on a lower I had. Went down to the range to kill some paper and had nothing but problems at the start. First off, do not use an H2 buffer or the Super 42 setup. It's too strong. After that debackle of failure to feed and failure to lock to the rear...... I put in just a standard carbine spring and buffer. Should have worked right? Well sorta. Now I was just down to failure to lock to the rear.... hmmm. I take it apart and inspect, can;t find anything. Put it back together and just start running through rounds, after about the 100 round mark it started to run perfect. Continued to run another 400 rounds through it without any failures. So yea, love it now. (Posted on 3/27/2017)
Excellent Review by J
I bought one of these uppers for carbine build and it functions flawlessly. The fit and finish is excellent and it works just fine for me with a non-AP bolt. Rifle is fairly accurate as well. Very easy to keep it within 2.5 MOA with cheap ammo and a red-dot. (Posted on 3/3/2017)
EXTREME attention to detail! GREAT JOB A.P.!! Review by Phil
I just received the upper (along with a NiB BCG and waiting on a complete lower to finish the build) and I couldn't be more impressed. Finish is AMAZING! Feels like exactly what you want in your hand. This is the way reputations are earned! Great Job to the A.P. team! (Posted on 2/24/2017)
Great quality build Review by Wesley
Glad I was lucky enough to find this company online, this upper is nice and good quality, I like the design much more than the competitors, simply because its not rounded. Its sleek and good looking. Fires like a champ. Great customer service as well. (Posted on 8/2/2016)

5 Item(s)

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