The Aero Precision Complete Upper Receiver epitomizes speed, efficiency, and dependability for fashioning a semi-custom AR15 rifle. Crafted with meticulous precision, this 5.56 NATO M4E1 Threaded Complete Upper boasts a 16″ Mid-Length barrel and a 15″ ATLAS S-ONE handguard. Meticulously machined, comprehensively assembled, and subject to rigorous test-firing by skilled Aero Precision armorers, it guarantees unparalleled performance.
* Does not include Bolt Carrier Group or Charging Handle.
Includes:
- M4E1 Threaded Assembled Upper Receiver – Anodized Kodiak Brown
- 15″ M-LOK ATLAS S-ONE Handguard – Anodized Kodiak Brown
- 16″ 5.56 NATO Mid-Length Barrel
- Low-profile Gas Block and Gas Tube
- Standard A2 Flash Hider
M4E1 Threaded Upper Receiver Features:
- New enhanced forging gives the upper receiver a “billet look.”
- M4 Feed ramps
- .250 takedown pin holes
- Laser engraved T-marks
- Includes port door and forward assist installed
ATLAS S-ONE Handguard Features:
Aero Precision’s ATLAS attachment system is a secure and dependable mounting platform, maintaining a slim profile while still providing the strength and stability customers have grown to love from Aero Precision handguards.
- 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
5.56 NATO Barrel Features:
- 5.56 NATO 1/7 twist, 4150 CrMoV, QPQ finish
- .750 gas block journal
- Mid-Length gas system
- M4 Feed Ramp Extension
- HP and MPI tested



