Radical Firearms .300 BLK Heavy Barreled AR-15 Upper - RPR Handguard - 16"

Manufactured by Radical Firearms
Manufactured by Radical Firearms
2 Reviews

In Stock

Orders of non-FFL items will ship same-day if placed before 3:30pm CST (M-F). FFL orders will ship within 5 business days if transfer details are provided.

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NOTE: This AR-15 barreled upper does not include a bolt carrier group or charging handle.

The Radical Firearms 16" .300 BLK Heavy Barreled Upper Receiver is a MIL-STD drop-in solution for your next AR build. This MIL-STD barreled upper receiver provides an outstanding solution for any budget with its quality material craftsmanship and Radical's lifetime warranty. This 16" 300BLK HBAR Barreled Upper includes a 15" RPR free float rail system that'll keep your hands cool while increasing accuracy. Complete the build with your favorite lower receiver, charging handle, bolt carrier group, and sights, then head for the range.

  • Chambered in 300BLK with 1:8 twist rate
  • 16" 4140 chrome moly vanadium steel HBAR barrel with Melonite finish
  • 5/8x24 thread pitch - A2 flash hider
  • 15" free float RPR M-LOK handguard
  • Pistol length gas system
  • Forged 7075-T6 aluminum material with type III anodizing
  • M4 MIL-STD receiver style
  • M4 Feed ramp
  • .750 low-profile gas block
See More


Barrel CoatingMelonite
Barrel ContourHBAR
Barrel Length16
Barrel Material4140 Chrome Moly Steel
BrandRadical Firearms
Caliber Gauge300 Blackout
FinishHardcoat Anodized
Gas System LengthPistol
Thread Pattern5/8 X 24
Twist Rate1:8
California Prop 65 warning

 WARNING: This product can expose you to chemicals, which are known to the State of California to cause Cancer and Reproductive Harm. For more information go to www.P65Warnings.ca.gov.

Ratings & Reviews

2 reviews

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Great Service

by -

From wanting to purchase to receiving the upper receiver I am totally pleased with the whole process. Primary Arms is a special company with their service. Product looks like good quality. Only problem is at this time I haven’t had a chance to get to the range with it.

Excellent Value

by -

This 16 inch barreled upper is well built and extremely accurate. Exceptional value for the price.