Faxon Duty Series 12 inch 8.6 Blackout AR10 barrel, 1:3 twist, 4150 CMV, QPQ nitride, pistol gas — primary product photo.

FAXON DUTY SERIES GUNNER PROFILE 12" 1:3T PISTOL-LENGTH 8.6 BLK AR10 BARREL

Faxon
SKU:
10A863P12NGQ
|
UPC:
816341026377
Availability:
Usually ships within 2 business days when available.
$238.00
(6 reviews)
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Description

 

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

Platform / Series
AR10 — Duty Series
Caliber
8.6 Blackout (8.6 BLK)
Length
12"
Twist Rate
1:3
Profile
Big Gunner
Material
4150 CMV (Chrome Moly Vanadium)
Rifling
Button Rifled
Finish
Salt Bath Nitride (QPQ) — inside & out
Gas System
Pistol-length
Gas Block Diameter
.875"
Gas Block Journal Length
1.9"
Muzzle Threads
M18x1.5 (tapered shoulder; adapter included)
Extension
Standard DPMS Gen 1 .308 Extension — Black Oxide
Inspection
Magnetic Particle Inspected (MPI)
Crown
11° Target Crown (non-recessed)
Weight
2.0 lbs
MSRP
$238.00

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.

8.6 Blackout cartridge drawing reference for ammunition specification

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/

 

 

Warranty Faxon Lifetime Guarantee. Covers manufacturing and material defects to the original purchaser. Excludes damage from misuse, neglect, non-standard ammunition, or modifications. Register your product at faxonfirearms.com/product-registration to expedite service. For purchases through dealers or distributors, warranty repairs are handled directly by Faxon Firearms; refunds must be processed through the selling entity. Full policy: faxonfirearms.com/warranty-privacy-terms/