M4E1 Enhanced 18" 5.56 Rifle Length Complete Upper Receiver

Aero Precision 18" 5.56 Rifle Length Complete Uppers

M4E1 Enhanced 18" 5.56 Rifle Length Complete Upper Receiver Product Sku: APPG600251P8

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
  • 18" 5.56 Rifle Length CMV Barrel
  • Low Profile Gas Block and Rifle 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

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 (Anodized only)
  • 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

Enhanced Handguard Features:

  • 1pc free float design
  • Rail is Machined from 6061-T6 Aluminum
  • 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

18" 5.56 Rifle Length Barrel Features:

  • 5.56 Nato 18" Rifle Length Barrel
  • 4150 CrMoV w/ QPQ finish
  • 1/7 twist
  • .750 gas block journal
  • Rifle length gas system
  • M4 Feed Ramp Extension
  • HP and MPI tested
  • Standard A2 flash hider
Made In America? Yes
Platform AR15
Series M4E1
Caliber 5.56 NATO
Barrel Length 18"
Weight(s) KeyMod: 65.9 oz / M-LOK: 65.9 oz / Quad Rail: 68.3 oz
Other No

Customer Reviews

6 Item(s)

Flawless Review by Kevin
This was my first AR15 build. I built an all Aero AR (minus furniture and trigger) and I have had the rifle for over a year now and never had any firing/cycling issues. The gun works flawlessly and is also one of the smoothest shooting ARs that I have fired. I will only but Aero Upper and lower parts now. (Posted on 11/25/2016)
Fantastic Review by Jason
I bought the 18" .223 Wylde complete upper to put on an Aero lower I built. Fantastic quality and shoots better than me. (Posted on 11/2/2016)
Great upper! Review by whispershot
This is an awesome upper. The barrel (because of the 4150 and the QPQ treatment) is of the highest quality. I just received this upper a couple of days ago, so I've only had a chance to shoot it at 25 meters so far. At that short distance, I can put rounds in the same hole all day long. I can't wait to see what the accuracy is at 100m; I anticipate a sub MOA rifle. The price of this upper is a steal considering it's high quality. I will be buying more AERO parts and rifles. The upper is a little heavy, but I wouldn't trade the weight for the quality. Awesome upper! (Posted on 5/7/2016)
Handguard and forward assist screws loosened up Review by Sean
Received complete upper in good condition ,product is good but need to pay attention securing all screws ( handguard and forward assist screws loosen up after 100 rds ) (Posted on 4/10/2016)
m4e1 complete upper Review by Charles
Top notch upper. I also purchased the nickel boron bcg to go with it and could not be happier. The only complaints I've read about aero was the time it takes to process the order and ship. My concerns were put to rest , I received my order in 5 business days with the 2 day usps shipping option. If you are considering buying something from aero, do it. You won't be disappointed if the quality and precision of my upper and bcg are any indicators of quality throughout their product line. (Posted on 2/14/2016)
Amazing quality Review by Armando
I just got my complete upper today. I ordered the 18" 5.56 Black M-Lok upper for a new build. It was hard finding what I wanted in stock but once it became available I purchased it. I had also considered buying all the parts and assembling my own but it was going to end up being a whole lot more expensive than the complete package they offer here. This is such a good deal.

The upper is built to quality standards. It fit my 80% lower perfectly with no lateral play. The action is smooth and it shoots true. Took about 10 minutes to get it zeroed in and I've put 100 rounds in the black out to 500yds since.

I can't say enough good things about this upper, and the company all together.

Thank you,
Armando O. (Posted on 1/28/2016)

6 Item(s)

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