Aero Precision - M4E1 Threaded Complete Upper, 11.5" 5.56 Barrel, 9" ATLAS R-One M-LOK Handguard

Aero Precision
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(1 review)
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This complete upper includes the new ATLAS R-ONE Handguard! The R-ONE handguards are designed with size and weight in mind, while still providing plenty of real-estate to accommodate any attachment needs the end user may have. The 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
  • 9" ATLAS R-ONE M-LOK Handguard
  • 11.5" 5.56 CMV Barrel
  • Low Profile Gas Block and Carbine Length Gas Tube
  • Product comes assembled
  • Does NOT include BCG and Charging Handle

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 R-One Handguard Features:

  • Full top picatinny rail for optional attachments
  • 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

11.5" 5.56 Barrel Features:

  • 5.56 Nato 11.5" Barrel, 1/7 twist, 4150 CrMoV, QPQ, gas port drilled
  • Government Profile
  • .750 gas block journal
  • Carbine length gas system, .0785 gas port
  • M4 Feed Ramp Extension
  • HP and MPI tested
  • Standard A2 flash hider
5.56 NATO


  • 5
    Absolutely great company and upper!

    Posted by Bruce Dilley-Miranda on Dec 14th 2023

    The Aero precision 11.5 M4e1 is a super nice Upper Receiver. The barrel is very accurate I'm getting 1 in groups at 100 yrds easy with a g30 3x. It feels solid and it's very reliable. The handguard is nice and has anti rotation tabs. I will buy more Aero From Grayman BABY