Aero Precision M4E1 16" 5.56mm ATLAS R-ONE Mid-Length Upper Receiver

This complete upper receiver incudes an HBAR profile barrel that is laser marked "HBAR".

Includes:

• M4E1 Enhanced Assembled Upper Receiver
• 15" ATLAS R-ONE M-LOK Handguard
• 16" 5.56 HBAR barrel
• Low Profile Gas Block and Mid-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.

M4E1 Upper Features:

• Forged from 7075 T6 aluminum
• Precision machined to M4E1 specs
• M4 feedramps
• Matte black hard coat anodized Mil 8625 Type 3 Class 2
• Laser engraved T-marks
• Comes assembled, with port door and forward assist installed
• Accepts standard AR15/M16 components
• Handguard mounting platform is forged into the receiver
• Works with Aero Precision handguards but also fits most BAR-system handguards
• Barrel nut and wrench are included

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
• 1.3" Inside diameter
• 1.5" Outside diameter
• Compatible with mil-spec AR15 upper receivers and barrels
• MLOK attachment points

16" 5.56 HBAR Barrel

• 5.56 Nato 16" Barrel, 1/7 twist, 4150 CrMoV, QPQ, gas port drilled
• .750 gas block journal
• Mid-Length Gas System
• M4 Feed Ramp Extension
• HP and MPI tested
• Standard A2 flash hider