This assembled upper includes Aero Precision’s 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.

INCLUDES:

• M4E1 Threaded Assembled Upper Receiver - Anodized Black or Cerakote FDE depending on model.
• 15" ATLAS R-ONE M-LOK Handguard with 16"CMV Barrel OR
• 15" ATLAS R-ONE M-LOK Handguard 18" Rifle Length CMV Barrel OR
• 10” ATLAS R-ONE M-LOK Handguard 10.5” Carbine Length M4 Barrel
• Low Profile Gas Block and Mid Pencil, Mid-Length, or Rifle Length Gas Tube depending on configuration
• Product comes assembled
• This assembled upper does not include BCG or Charging Handle.
• The muzzle brake that comes with this assembled 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 16"" 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 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

10” and 11.5 ” Carbine Length Barrel Features

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

• Mid-length, 1/7 twist, 4150 CrMoV, QPQ, gas port drilled
• .750 gas block journal
• Mid-length gas system, .0785 gas port
• M4 Feed Ramp Extension
• HP and MPI tested
• Standard A2 flash hider

16" Mid-Length Barrel Features:

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

18" Rifle Length Barrel Features:

• 18" Rifle Length Barrel
• 4150 CrMoV w/ QPQ finish
• 1/7 twist
• .750 gas block journal
• Rifle length gas system
• M4 Feed Ramp Extension
• HP and MPI tested
• Standard A2 flash hider