M4E1 Threaded 12.5" 5.56 Carbine Length Complete Upper Receiver w/R-ONE Handguard

This complete upper includes our 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. 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 Upper Receiver
• 12" M-LOK ATLAS R-ONE Handguard
• 12.5" 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

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
• Learn More about our NEW ATLAS Handguards

12.5" 5.56 CMV Carbine Length Barrel Features:

• Chamber: 5.56
• Length: 12.5"
• Twist: 1 in 7
• Threading: 1/2"x28
• Material: Chrome Moly Vanadium
• Finish: QPQ corrosion resistant finish both inside and out
• Gas Block: .750
• Gas System Length: Carbine
• Weight: 22oz
• M4 Barrel Extension
• HP and MPI Tested