Radical Firearms 8.5" 300 BLK Complete Upper Pistol Length - M-LOK FCR Rail

Manufactured by Radical Firearms
Manufactured by Radical Firearms
4 Reviews

Out of Stock

NOTE: Limit 1 per household. Quantities exceeding 1 will not allow checkout.



The Radical Firearms 8.5" 300 BLK HBAR Complete Upper is a law enforcement grade, drop-in solution for your next AR build. Crafted with quality materials and covered by Radical’s lifetime warranty, this MIL-SPEC upper receiver provides an outstanding solution for any budget. Arrives at your door with the hard work done. Finish the build with your favorite lower receiver and sights, then head for the range!

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.

  • 8.5" 41V50 chrome moly vanadium steel HBAR contour barrel
  • Chambered in 300 BLK with a 1:8 twist rate
  • M16 cut bolt carrier group with Melonite finish
  • BCG high pressure tested and magnetic particle inspected
  • Standard charging handle
  • 5/8x24 A2 flash hider
  • 7" Radical Firearms M-LOK FCR rail
  • Gen 3 rail mounting system
  • Made in the U.S.A. in Stafford, Texas!

The Radical Firearms FCR system is a slim handguard that provides the weight savings you want without sacrificing any of the mounting possibilities you require. This freefloat design offers a monolithic Picatinny rail and plenty of M-LOK attachment points for all your gear.
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Barrel ContourHBAR
Barrel Length8.5
Barrel Material41V50 Chrome Moly Vanadium Steel
BrandRadical Firearms
Caliber Gauge300 Blackout
Gas System LengthPistol
Gas System TypeDirect Impingement
Handguard7 in Radical M-LOK FCR Rail
Muzzle DeviceA2 Flash Hider
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

Check your barrel

by -

Check your barrel. I ordered 2. One had an 1:8 twist, one had 1:7 twist

Poor upper machining

by -

The machining on the upper was very poor. The takedown pin holes were misaligned on front and rear. It would need to have about 1/32 taken off both sides of the rear mounting block just to properly seat into any of the 3 lowers I have. It seems to be a good barrel and guard. Not so sure the upper was machined well.

better the 2nd time

by -

After the initial issues where I was sent 2 uppers with 2 different barrels, I have had good results with my original 1:7 upper. I haven't shot the replacement upper, but it looks fine cosmetically

It just runs and runs


I already have the 5.56 version of this upper and now I have the 300 BLK version. So far 800 rounds, no malfunctions. It is running flawlessly with a Spike’s Tactical lower. My favorite thing about this entire upper is how the M-LOK free-float rail feels as if it were designed to accommodate a Magpul AFG-2 angled foregrip. It fits like a glove and makes for such a cool and clean look that sets it apart from the others. Plus this makes it incredibly ergonomic and comfortable to handle.