Brownells 75th Anniversary - A Shooting Heritage

Enhanced upper receiver is everything you need to convert your AR carbine or pistol to the exciting new 300 AAC Blackout (300 BLK) round. Features a nitrided, 1-7 twist barrel with M4 feed cuts, a Knight’s Armament URX free-floating handguard, and AAC'S 51T flash suppressor. 51T accepts the AAC 762-SDN-6 sound suppressor to make the gun nearly silent when used with subsonic ammunition. The nitride treated bore and chamber provide excellent corrosion resistance and a longer service life than standard chrome-lined barrels, and the full-profile M16 bolt/carrier group allows these uppers to function on a full-auto M16 lower as well as on semi-auto guns. Available with standard 16" Carbine barrel, designed to function with subsonic and supersonic ammunition. All barrels feature a 1-7 twist.

MPW 5.56 Upper Receiver

  • 5.56 NATO Complete upper receiver for AR-15/M16 platforms
  • 16” Nitrided 4150 CMV steel barrel
  • M4 feedramps
  • Includes AAC 51-tooth Blackout Flash Suppressor
  • Knight’s Armament free-floating URX rail
  • M16 Bolt Carrier Group
  • Bolt is Carpenter 158 steel and includes improved extractor o-ring
  • Internally chrome lined bolt carrier
  • Heat-treated gas-key with proper staking
  • Full auto chamber dimensions
  • Carbine length gas system
  • Charging handle included

SPECS: Receiver – Aluminum, M4 Feedramps, Picatinny Top Rail, Matte Black Anodizing, M16 Bolt Carrier Group. Handguards –Freefloat URX II (12.5" and 16”) or URX III (9”). Barrel – 16” or 9” nitride 300 Blackout, 5/8-24 threaded muzzle, 1-7 twist, 51T Blackout Flash Hider.


Discontinued by the Factory

Product has been discontinued and no longer available.