M4E1 Threaded 16" 5.56 Mid-Length Complete Upper Receiver w/ ATLAS S-ONE Handguard

Aero Precision AR15 Gen 2 Complete Upper, 16" 5.56 Mid-Length Barrel, ATLAS S-ONE Handguard

M4E1 Threaded 16" 5.56 Mid-Length Complete Upper Receiver w/ ATLAS S-ONE Handguard Product Sku: APPG700208

This complete upper includes our new ATLAS S-ONE Handguard! The S-ONE line of handguards are designed with size and weight in mind, providing the perfect addition to your lightweight build. Our proprietary ATLAS attachment system is a durable and dependable mounting platform, maintaining a slim profile while still providing the strength and stability customers have grown to love from Aero Precision handguards.


  • M4E1 Threaded Assembled Upper Receiver
  • ATLAS S-ONE Handguard of choice
  • 16" 5.56 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

M4E1 Threaded Upper Receiver Features:

  • New enhanced forging that gives the upper receiver a "billet look"
  • New picatinny profile that blends seamlessly with our Enhanced Series Handguards
  • M4 Feedramps
  • .250 takedown pin holes
  • Laser engraved T-marks
  • Includes port door and forward assist installed

ATLAS S-ONE Handguard Features:

  • Front and rear picatinny rail
  • Eliminated center of top rail for weight reduction
  • Indexing grooves in 12:00 position for positive grip control
  • Quick disconnect sling socket at the 3, 6 and 9 o’clock positions
  • Compatible with low profile gas blocks
  • 1.3” Inside diameter
  • 1.5” Outside diameter
  • Compatible with mil-spec AR15 upper receivers and barrels
  • Learn More about our NEW ATLAS S-ONE Hanguards

16" 5.56 Mid-Length Barrel Features:

  • 5.56 NATO 16" Midlength, 1/7 twist, 4150 CrMoV, QPQ, gas port drilled
  • .750 gas block journal
  • Mid-length gas system, .0785 gas port
  • M4 Feed Ramp Extension
  • HP and MPI tested
  • Standard A2 flash hider
Made In America? Yes
Platform AR15
Series ATLAS
Caliber 5.56 NATO
Barrel Length 16"
Weight(s) 12" - 52.7 oz / 15" - 53.6 oz
Other NOTE: Weights above include Gen 2 Upper, Handguard, Barrel, Muzzle Brake and Mounting Hardware.

Customer Reviews

2 Item(s)

Great looks, Great Function, Great Specs! Review by Jack
I recently received this 16" mid-length Atlas upper and it is awesome. Fit and finish are flawless, the hand guard is super light and very thin, and barrel nut-to-hand guard appears very strong and sturdy. The only issues, and they are minor, I had with the upper was a muzzle device that was overly tightened causing the crush washer to be too crushed and the inability to remove the port door rod unless the barrel nut is backed off so could be "timed" with the rod in order to remove it. Consequently, I had subtract 1 star from an otherwise 5 star quality rating. I've previously ordered two other uppers (an M4E1 18" .223 Wylde Complete Upper Receiver and an M4E1 16" 5.56 Mid-Length Complete Upper Receiver) and both earn 5 star across the board. AERO's quality and value are without equal. (Posted on 1/11/2018)
Just arrived Review by JOHN
It will be a while till I can shoot her but it looks great.Ill get a lower tomorrow then all i need is sights,ammo & mags (poor person problems) Its awesome having the first run of a brand new upper.I will update next month. ATLAS RIIIIISSSSSEEEEEE!!!! \m/ \m/ (Posted on 9/11/2017)

2 Item(s)

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