Aero Precision M4E1 Threaded 5.56mm Complete Upper Receiver 16in Mid Length Pencil Barrel 1-7 Twist A2 Flash Hider ATLAS R-ONE Handguard Black

Aero Precision M4E1 Threaded Complete Upper 16" 5.56 Mid Pencil Length Barrel, ATLAS R-ONE 15" M-LOK HG - AnodizedThis complete 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 Black15" ATLAS R-ONE M-LOK Handguard with 16" 5.56 CMV Barrel OR15" ATLAS R-ONE M-LOK Handguard 18" 5.56 Rifle Length CMV BarrelLow Profile Gas Block and Mid Pencil, Mid-Length, or Rifle Length Gas Tube depending on configurationProduct comes assembledThis complete upper does not include BCG or Charging Handle.The muzzle brake that comes with this complete 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 HandguardsM4 Feedramps.250 takedown pin holesLaser engraved T-marksIncludes port door and forward assist installedATLAS R-ONE Handguard Features:Full top picatinny rail for optional attachmentsQuick disconnect sling socket at the 3, 6 and 9 o'clock positionsCompatible with low profile gas blocks1.3 Inside diameter1.5 Outside diameterCompatible with mil-spec AR15 upper receivers and barrels16" 5.56 Mid-Length Barrel Features:5.56 NATO 16" Mid-length, 1/7 twist, 4150 CrMoV, QPQ, gas port drilled.750 gas block journalMid-length gas system, .0785 gas portM4 Feed Ramp ExtensionHP and MPI testedStandard A2 flash hider18" 5.56 Rifle Length Barrel Features:5.56 Nato 18" Rifle Length Barrel4150 CrMoV w/ QPQ finish1/7 twist.750 gas block journalRifle length gas systemM4 Feed Ramp ExtensionHP and MPI testedStandard A2 flash hider