Buy now!
NOTE: This part features a colored anodized finish. These finishes are held to different aesthetic standards than parts finished in black anodizing or Cerakote. For more information on colored anodizing visit our Knowledge Center.
This complete upper receiver features the same tried-and-true construction and aesthetics as our M4E1 Threaded Upper Receivers, without provisions for a forward assist. 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.
Includes:
M4E1 Threaded Assembled No Forward Assist Upper Receiver
10.3" M-LOK ATLAS S-ONE Handguard
11.5" 5.56 Government Profile CMV Barrel, Carbine Length
Low Profile Gas Block and Carbine Length Gas Tube
AR15 A2 Birdcage Flash Hider
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 14.5" as defined by the ATF for a rifle build
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 Hanguards
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