M4E1 Threaded 10.5" 5.56 Complete Upper Receiver w/R-ONE Handguard

This complete upper includes our 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. 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
• ATLAS S-ONE Handguard of choice
• 10.5" 5.56 CMV Barrel
• Low Profile Gas Block and Carbine 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
• The muzzle brake that comes with this complete upper receiver is NOT pinned nor welded to this barrel.

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

10.5" 5.56 Barrel Features:

• 5.56 Nato 10.5" Barrel, 1/7 twist, 4150 CrMoV, QPQ, gas port drilled
• .750 gas block journal
• Carbine length gas system, .0785 gas port
• M4 Feed Ramp Extension
• HP and MPI tested
• Standard A2 flash hider