FAXON DUTY SERIES GUNNER PROFILE 12" 1:3T PISTOL-LENGTH 8.6 BLK AR10 BARREL
Faxon
$238.00
(6 reviews)
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Faxon
FAXON DUTY SERIES GUNNER PROFILE 12" 1:3T PISTOL-LENGTH 8.6 BLK AR10 BARREL
Faxon Duty Series AR-10 Barrel — 12" 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 12" 8.6 Blackout (8.6 BLK) AR-10 barrel is purpose-built for compact setups where reliability, durability, and handling come first. With a fast 1:3 twist, pistol-length gas, and Big Gunner contour, it’s a strong fit for short 8.6 BLK builds—including suppressed configurations (with proper tuning and alignment).
Duty Series barrels are made from 4150 CMV (Chrome Moly Vanadium), a tough, heat-tolerant steel widely chosen for hard-use barrels. 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, proven interface, and every barrel is MPI inspected.
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: Great for hard use and heat management in compact barrels that may see fast strings or frequent suppression.
- QPQ nitride inside & out: Corrosion resistance and reduced fouling for easier maintenance and long service life.
- Button rifling: A proven rifling process that supports consistent performance across a wide range of ammunition.
- Compact handling: 12" length with Big Gunner contour balances maneuverability and practical stiffness.
- Simple, durable interfaces: Black oxide extension and common AR-10/LR-308 pattern compatibility (verify fitment).
Ideal Use Cases
- Compact 8.6 BLK builds: Pistol gas and 12" length for maneuverability and portability.
- 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 workhorse combo for high round counts and varied environments.
- Field carry / truck gun style setups: Short 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 12" 8.6 BLK barrel fit my AR-10 / LR-308?
This barrel uses a DPMS Gen 1 .308 extension. Always verify compatibility with your receiver set, bolt, and components before assembly.
Why choose 4150 CMV for a compact 8.6 BLK barrel?
4150 CMV is tough and heat-tolerant, which can be especially beneficial in short barrels that may see faster strings, frequent suppression, or hard-use conditions.
Is this barrel suppressor-ready?
The muzzle uses M18x1.5 with a tapered shoulder (adapter included). Confirm your muzzle device compatibility and ensure proper alignment before firing, especially with suppressors.
What does QPQ nitride do for Duty Series barrels?
Salt bath nitride (QPQ) increases corrosion resistance, reduces fouling, and improves surface wear resistance—helpful for rifles used in varied weather, storage, and frequent cleaning cycles.
Is 8.6 BLK SAAMI certified?
At the time of release, 8.6 BLK is not SAAMI certified. Use appropriate caution while firing and when using reloaded ammunition, and follow safe load practices.
Warranty: Backed by the Faxon Lifetime Guarantee. Full details: https://faxonfirearms.com/warranty-privacy-terms/
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Backed by the Faxon Lifetime Guarantee. Full details available at https://faxonfirearms.com/warranty-privacy-terms/
- 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:
- 2.0 lbs
- Barrel Length:
- 12"
Reviews
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12" 8.6 Blackout
The barrel itself is top notch. Nice and heavy and I can't find a thing wrong with it. After 2 months of shopping and meticulously putting parts together I have finally built my AR pistol and gotten a bit of ammo from Gorilla ammunitions. Took it out to the range today and to my surprise this thing has WAY less recoil and retort/noise than I was expecting. Shoots like an absolute dream. I've only shot subsonic ammo so far so maybe with the super sonic ammo it's have a little more flare and kick to it but from what I've shot so far, great stuff indeed.
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Quality
Been actively building and re-barreling all types of firearms for quite some time and was really impressed with the fit and finish of this barrel.
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Faxon 12" Big Gunner 8.6 BLK barrel
So glad to see Faxon come out with these and be on top of this new arising market. I wanted the 12" as most work seems to be done with it at the moment. Like all the Faxon product I have purchased it's top quality and having a Faxon bolt ensures everything will work together.
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FAXON 12" BIG GUNNER, 8.6 BLK, PISTOL LENGTH, 4150, NITRIDE, AR-10
Fit and finish are phenomenal, slides tightly into upper. Everything you could ask for in an 12" 8.6 blk barrel.
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Observations
Disappointed tht the barrel doesn’t come dimpled, also felt Faxon should offer readily available thread adapters for the muzzle, not everyone uses a suppressor. The twist rate for some is undesirable. An offering of a slower twist rate such as 1/7 would enhance desirability due to cost of monolithic projectiles. Overall quality and build tho is excellent and up to Faxon standards. In time I can see these factors reimagined which will help the cartridge succeed.
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FAXON 12" BIG GUNNER, 8.6 BLK Barrel
Craftsmanship is impeccable, can’t wait to start my next build with it.