Due to increased demand, please expect delays in shipping times. Washington State Magazine Orders will be prioritized so they can be delivered before July 1, 2022. We are no longer accepting orders on magazines with 10+ capacity to the state of Washington.

Out of stock
Bushmaster .223 Rem/5.56 16" Barrel Flat-Top Complete Upper Assembly - 91823
Out of stock

Bushmaster .223 Rem/5.56 16" Barrel Flat-Top Complete Upper Assembly - 91823

SKU 792651
Brand Bushmaster
Model Number 91823
UPC 604206918239
Customers must read Compliance Information before purchasing.

Product Details


  • Type: Flat-Top
  • Handguard: Black Carbine Length
  • Caliber: 223 Remington/5.56x45mm NATO
  • Barrel Type: M4 Profile
  • Barrel Length: 16"
  • Barrel Material: 4150 Chrome Moly Vanadium Steel
  • Muzzle Type: A2 Flash Hider
  • Receiver Type: A3 Flat-Top
  • Receiver Finish: Hardcoat Anodized Black
  • Barrel Finish: Black



  • Built on the versatile Bushmaster modular MSR upper platform
  • Barreled upper receivers can be used on existing MSR-type lower receivers
  • Bushmaster 4150 chrome moly vanadium steel barrels feature hard-chrome lining in both bore and chamber for extended barrel life
  • All receivers feature integral brass deflectors and hard anodized finish
  • Each assembly is factory headspaced, proofed, test fired and ready to use
  • 16 inches M4 barrel chrome-lined in both bore and chamber
  • Front sight post with bayonet lug
  • Bolt carrier assembly


Q & A


All NFA Rules Apply.
These items are controlled by the U.S. Government and authorized for export only to the country of ultimate destination for use by the ultimate consignee or end-user(s) herein identified. They may not be resold, transferred, or otherwise disposed of, to any other country or to any person other than the authorized ultimate consignee or end-user(s), either in their original form or after being incorporated into other items, without first obtaining approval from the U.S. government or as otherwise authorized by U.S. law and regulations.