Faxon Duty Series 16" Pencil, 5.56 NATO, Mid-Length, 4150 QPQ Nitride AR-15 Barrel

(33 reviews)
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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 Type: Button Rifled 
  • Barrel Caliber: 5.56
  • Barrel Twist: 1:8
  • Barrel Length: 16”
  • Barrel Profile:  Pencil
  • Barrel Gas System: Mid
  • Inside Finish: Nitride
  • Outside Finish: Nitride
  • Muzzle Thread: 1/2-28
  • Gas Block Diameter: .625" 
  • Gas Block Journal Length: 1.1"
  • Barrel Extension: M4 
  • Weight:  1.20  lbs
  • Magnetic Particle Inspected!
  • 11-degree Target Crown


Barrel Caliber:
5.56 NATO
Barrel Profile:
Barrel Material:
4150 CMV
Rifling Twist Rate:
Muzzle Thread:
Gas Block Diameter:
Gas System Length:
Barrel Length:
Barrel Length Range:
16" - 18"


  • 5
    Perfect for a light weight build

    Posted by Anton Jurun on Jan 30th 2024

    My second time getting one of these, and they always impress with their light weight and consistent accuracy.

  • 5
    very nice product and very well made it is the 4th pencil barrel that I have bought from Faxon.

    Posted by Jerry J Jacques on May 24th 2023

    I have not shot this barrel yet but have 3 other Faxon Pencil barrels and they all shoot excellent, I love these barrels as they are light weight and still shoot well.

  • 5
    16" pencil-profile barrel, cal. 5.56x45

    Posted by David Burch on May 4th 2022

    Fit and finish are top-notch, as expected from Faxon. Initial testing with 55-grain FMJ handloads yielded accuracy as good as the Gunner-profile barrels on my other AR rifles. But this barrel is a bit lighter, and when combined with a minimalist stock and short free-float handguard, the resulting weapon is quick to the shoulder, balances nicely, and points naturally.

  • 5
    5.56 pencil barrel

    Posted by Kenneth Taylor on Feb 23rd 2022

    Nice finish, lite weight, good profile. Will buy again

  • 5
    We bought two

    Posted by David Garlisch on Feb 11th 2022

    We liked this barrel so much, we bought a second one as a backup to the one my Mrs installed on her AR-15. We have been getting great groups! Highly recommend.

  • 5
    Very Light. Very accurate. Very well machined

    Posted by Okie on Jan 16th 2020

    Great barrel. Well machined. Very light and BODA accui. Awesome

  • 4
    Good quality, but overgassed

    Posted by Frank Holub on Jan 12th 2018

    I'm overall satisfied with my Faxon pencil barrel, but the one issue I have with it is that it's severely overgassed, causing significant bolt bounce during cycling. The issue was fixed with an adjustable gas block, but it shouldn't really be an issue in the first place with the common .223 and 5.56 loads I was using. Other than that, the barrel is made of quality materials, the finish is impeccable, and accuracy is good too, though anyone buying a pencil barrel should be aware it heats up fast, opening groupings up a bit once hot.

  • 5
    Pencil barrel

    Posted by Kurl on Sep 15th 2017

    Nice fit and finish, fairly light.

  • 5
    Pencil 556

    Posted by Kurl on Sep 15th 2017

    Very elegant and cleanly machined. The high gloss finish is also a nice touch.