FAXON DUTY SERIES GUNNER PROFILE 8" 1:3T PISTOL-LENGTH 8.6 BLK AR10 BARREL
Faxon
Faxon Duty Series AR-10 Barrel — 8" 8.6 Blackout (1:3 Twist, Pistol Gas)
4150 CMV steel • Button rifled • Salt bath nitride (QPQ) inside & out • DPMS Gen 1 .308 extension (black oxide) • MPI inspected • 11° target crown • Big Gunner profile • Pistol-length gas • .875" gas block journal • M18x1.5 muzzle with tapered shoulder (adapter included)
The Faxon Duty Series 8" 8.6 Blackout (8.6 BLK) AR-10 barrel is built for ultra-compact 8.6 BLK setups where maneuverability and reliability are the mission. With a fast 1:3 twist and pistol-length gas, this barrel is tuned for modern 8.6 Blackout builds—including suppressed configurations (with proper tuning and alignment).
Duty Series barrels are made from 4150 CMV (Chrome Moly Vanadium), a proven steel selected for toughness and heat tolerance. The bore is button rifled, then treated with salt bath nitride (QPQ) inside and out to improve corrosion resistance, reduce fouling, and support long service life. A black oxide coated DPMS Gen 1 .308 extension provides a durable, straightforward interface, and every barrel is MPI inspected for quality confidence.
Proudly American Made by a family-owned manufacturer in Greater Cincinnati, Ohio. Learn more about the 8.6 BLK cartridge: click here.
Why Duty Series Specs Shine
- 4150 CMV steel: A rugged, heat-tolerant alloy well-suited for hard-use shooting and compact barrels that may see faster strings.
- QPQ nitride inside & out: Corrosion resistance and reduced fouling for easier maintenance and long service life.
- Button rifling: Proven process that supports consistent performance and broad ammo compatibility.
- Compact handling: 8" length with Big Gunner contour balances maneuverability and practical stiffness.
- Durable interface: Black oxide extension with DPMS/LR-308 pattern compatibility (verify fitment).
Ideal Use Cases
- Ultra-compact 8.6 BLK builds: Pistol gas and 8" length for maximum maneuverability.
- Suppressed shooting: QPQ finish helps reduce corrosion and fouling; tune gas/buffer as needed and confirm alignment.
- Training and hard use: 4150 CMV + QPQ is a durable workhorse combination for demanding conditions.
- Vehicle / pack / field carry setups: Compact overall length without sacrificing capability.
Specifications
Build note: Function and tuning vary by ammunition, buffer system, and suppressor setup. Always verify headspace with proper gauges and confirm muzzle-device alignment before use.
Consumer Note:
At the time of release, 8.6 BLK is not SAAMI certified. Please use appropriate caution while firing and when using reloaded ammunition. Learn more and find load data provided by Q by clicking here.
PLEASE NOTE:
We have noticed inconsistencies with 8.6 BLK ammunition available on the market. Ammunition that does not match the cartridge print below cannot be guaranteed to function in our rifles or barrels.
Using cartridges made specifically for semi-auto rifles may cause light primer strikes in bolt action rifles due to hard primers.
If you have any questions, please contact customerservice@faxonfirearms.com.

Frequently Asked Questions
Will this 8" 8.6 BLK barrel fit my AR-10 / LR-308?
Why choose 4150 CMV for a compact 8.6 BLK barrel?
Is this barrel suppressor-ready?
What does QPQ nitride do for Duty Series barrels?
Is 8.6 BLK SAAMI certified?
Warranty: Backed by the Faxon Lifetime Guarantee. Full details: https://faxonfirearms.com/warranty-privacy-terms/
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- Caliber:
- 8.6 BLK
- Barrel Profile:
- Big Gunner
- Barrel Material:
- 4150 CMV
- Outside Finish:
- QPQ Nitride
- Rifling Twist Rate:
- 1:3
- Muzzle Thread:
- M18x1.5
- Gas Block Diameter:
- .875"
- Gas Block Journal Length:
- 1.9"
- Barrel Weight:
- 1.6 lbs
- Barrel Length:
- 8"
Reviews
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Great for 8” 8.6 BLK build.
Grabbed this barrel while on sale for an 8” 8.6 BLK build. It’s sold and I can’t wait to test it.
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Extremely solid
The quality on these barrels is off the charts, but be warned they are not light lol. I know the weight is listed but you really can’t picture how heavy these things are until you hold one. Really hoping this round takes off because I am impressed so far.
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Very nice
Seems to be very well made, haven't gotten to fire it yet as I am waiting on reloading dies.