This upper assembly includes Aero Precisions 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. Their 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.

NOTE: This upper assembly does not include BCG or Charging Handle.

Includes:

• M4E1 Threaded Assembled Upper Receiver
• ATLAS R-ONE Handguard of choice
• .300 Blackout CMV Barrel
• Low Profile Gas Block
• Product comes assembled
• The muzzle brake that comes with this upper assembly 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 Aero's 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

.300 Blackout Barrel Features:

• Twist: 1 in 7
• Muzzle: 5/8x24 Threaded
• Material: 4150 Crome Moly Vanadium
• Finish: QPQ corrosion resistant finish both inside and out
• Gas Block: .750
• Gas System Length: Pistol
• M4 Feed Ramp Extension, HP and MPI Tested, Standard A2 Flash Hider

8" .300 Blackout Barrel Features:

• Length: 8"
• Gas Port: .109
• Weight: 18oz

10" .300 Blackout Barrel Features:

• Length: 10"
• Gas Port: .0935
• Weight: 21oz

16” .300 Blackout Barrel Features:

• Length: 16"
• Weight: 29oz