Radical Firearms 300 BLK Barreled Upper - 8.5"

Manufactured by Radical Firearms
SKU: PABU8.5-300
MPN: PABU8.5-300
Manufactured by Radical Firearms
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NOTE: This upper receiver has a barrel that is less than 16” in length and is intended for use in AR pistol or legal short-barreled rifle builds. Other configurations may violate Federal law.

Quickly switch to a new caliber on your Mil-Spec AR-15 lower with the Radical Firearms 300 Blackout barreled upper receiver. It comes from the factory already assembled, so all you need is a bolt carrier group and charging handle, pin it to your existing lower and you are ready to go. This barreled upper receiver features an 8.5” barrel, so it must be pinned to a lower configured as a pistol or a registered SBR lower. The barrel features a heavy contour and a pistol length gas system in order to reliably cycle as well as a 1:8 twist rate to reliably stabilize the .30 caliber round. Attached to the end of the barrel is an A2 style flash hider and the entire barrel is Melonite finished for excellent corrosion resistance. Covering the barrel and gas system is the M-LOK handguard with minimal picatinny rail space to save weight. The picatinny top rail is continuous with the M4 flat top upper receiver and features anti-rotation tabs to ensure it stays indexed. If you are looking to breathe new life into your AR pistol with a fun to suppress caliber, you can’t go wrong with Radical Firearms.

  • Chambered in .300 Blackout
  • 8.5” HBAR barrel with A2 flash hider
  • 4140 Chrome Moly steel with Melonite finish
  • Pistol length gas system and 1:8 twist rate
  • 7" M-LOK handguard
  • M4 flat top upper receiver with forward assist and dust cover
  • Forged from 7075-T6 aluminum and hardcoat anodized
  • Does not include BCG or charging handle

The M4 flat top upper receiver and handguard are forged from 7075-T6 aluminum and machined to reach the final Mil-Spec dimensions and are hardcoat anodized for additional corrosion resistance. It features a Radical Firearms billet machined dimpled forward assist and a standard dust cover but does not come with a bolt carrier group or charging handle. Build your dream .300 Blackout AR pistol with this barreled upper receiver group from Radical Firearms.

Radical Firearms offers law enforcement grade hardware. Crafted with quality materials and covered by their lifetime warranty, Radical Firearms is an outstanding choice for any budget.
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AssemblyBarreled Assemblies
Barrel CoatingMelonite
Barrel ContourHBAR
Barrel Length8.5
Barrel LiningMelonite
Barrel Material4140 Chrome Moly Steel
BrandRadical Firearms
Caliber Gauge300 Blackout
Gas System LengthPistol
Gas System TypeDirect Impingement
Handguard7 in M-LOK Rail
Muzzle DeviceA2 Flash Hider
Thread Pattern5/8 X 24
Twist Rate1:8

WARNING: This Product can expose you to chemicals which is known to state of California to cause Cancer and Reproductive Harm. For more information, see www.p65warnings.ca.gov

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