Radical Firearms 10.5" 300 BLK 1:8 Pistol Length HBAR Barreled Upper - 10" Quad Rail

Manufactured by Radical Firearms
SKU: FU10.5-300HBAR-10FQR
MPN: FU10.5-300HBAR-10FQR
Manufactured by Radical Firearms
2 Reviews

Out of Stock

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



NOTE: This upper assembly has a barrel less than 16” in length. These uppers are intended for use in AR-15 pistols or legal short-barreled rifles. Other configurations may violate Federal law.

Does not include bolt carrier group or charging handle.

The Radical Firearms 10.5” 300 BLK HBAR Barreled Upper Receiver 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, charging handle, bolt carrier group, and sights then head for the range!

The Radical Firearms First-Gen Quad Rail delivers a plethora of mounting options with its full length Picatinny rails. Its roomy 1.8” inside diameter can accommodate most suppressors on the market.

  • 10.5" 41V50 chrome moly vanadium steel barrel with Melonite finish
  • Chambered in 300 BLK with 1:8 twist rate
  • 5/8x24 thread pitch A2 flash hider
  • 10" free float Radical Firearms Quad Rail
  • Made in the U.S.A. in Stafford, Texas!
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Barrel CoatingSalt Bath Nitride
Barrel ContourHBAR
Barrel Length10.5
Barrel Material41V50 Chrome Moly Vanadium Steel
BrandRadical Firearms
Caliber Gauge300 Blackout
Gas System LengthPistol
Gas System TypeDirect Impingement
Handguard10 in Quad 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

Ratings & Reviews

2 reviews

  • 4 stars
  • 0 reviews
  • 3 stars
  • 0 reviews
  • 2 stars
  • 0 reviews

Avoid at all costs

by -

Avoid this poorly made piece of crap at all costs. I have SBRs and was looking for a 10+ inch upper in 300 BLK. I keep telling myself “you get what you pay for” but I never learn. Spend the money on BCM, DD, Aero, or ANYONE else.
<br>The dust cover was bent, the finish was poor, but I could have forgiven that. The holes for the takedown pins were so poorly centered that they were off by a measurable 2mm. Impossible to secure any of my multiple AR lowers. I will never buy a product from Radical again.

Great upper


Perfect fit to my Aero Precision M4E1 Pistol Lower. Also threw it on a Spike’s lower and same result. Perfect fit. 200 rounds down range 0 malfunctions.