Faxon Duty Series 18", Pencil .308 WIN, Rifle-Length, 4150 QPQ Nitride AR-10 Barrel

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Faxon's pencil barrels are renowned for their lightweight performance. Fully stress relieved, we carefully designed the barrel's taper to remove weight while maintaining performance. The result is the lightest barrel in the industry - and one we are fully confident to put our Faxon shield on. 

Faxon's .308 barrels feature 1/10 twist rifling for full stabilization across all common .308 loadings. Our barrels are chambered to .308 Winchester SAAMI specification for maximum versatility. Manufactured in-house, these barrels are fully stress relieved, air-gauge tested, and 11 degree target crowned to ensure superior accuracy. 

Quality is imbued into our barrels from the start. We start with the best materials, either certified 4150 Mil-Spec steel or 416-R Stainless. From there, each barrel goes through a battery of tests at each operation until finished in Nitride and final inspected. All barrels are individually checked for headspace by precision custom hardened gauges. 

  • Barrel Material: 4150 CMV
  • Barrel Caliber: .308 WIN
  • Barrel Twist: 1:10
  • Barrel Length: 18”
  • Barrel Profile: Pencil
  • Barrel Gas System: Rifle
  • Inside Finish: Salt Bath Nitride          
  • Outside Finish: Salt Bath Nitride      
  • Muzzle Thread: 5/8x24 TPI
  • Gas Block Diameter: .750" 
  • Gas Block Journal Length: 1.1"
  • Barrel Extension: LR-308 (DPMS Compatible)
  • Weight: 1.97 lbs
  • Magnetic Particle Inspected
  • 11-degree Target Crown
Barrel Material:
4150 CMV
Barrel Type:
Button Rifled
Barrel Caliber:
.308 WIN
Barrel Length:
Barrel Twist:
Barrel Profile:
Barrel Gas System:
Inside Finish:
Salt Bath Nitride
Outside Finish:
Salt Bath Nitride
Muzzle Thread:
Gas Block Diameter:
Gas Block Journal Length:
Barrel Extension:
LR-308 (DPMS Compatible)
Barrel Weight:
1.97 lbs
Crown Type:
Recessed 11-degree Target Crown
Barrel Length Range:
16" - 18"


  • 3
    Barrel Gas Port Location

    Posted by Andrew on Dec 28th 2021

    The barrel appears to be made well. I scoped the inside to see the internal condition. The only issue I found was the gas port hole was cut in the middle of a land. I wonder if this will cause issues with accuracy as the gas hole can cause the spin to momentarily disrupt.

  • 5
    FAXON 18" Pencil, .308 WIN, Rifle-Length, 4150, Nitride

    Posted by Raymond on Dec 10th 2018

    Absolutely a beautiful barrel. I installed it in an Aero Precion enhanced upper and it resulted in a lightweight upper that balances perfectly. I haven't had a chance to shoot it yet but if it is as accurate as the pencil barrel I installed on my AR-15, it will be a tack driver.