Faxon 16" Pencil, 5.56 NATO, Mid-Length, 4150, Nitride w/ Pinned Gas Block AR-15 Barrel

(3 reviews)
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If you're looking for a more robust mounting method for your gas block... look no further. Pinning your gas block, in addition to the use of set screws, gives the user the extra piece of mind that your gas block won't shift or loosen while firing.

We took some of our most popular barrel models and took the biggest headache out of pinning your gas block by pre-notching the gas block journal and drilling corresponding holes in the included low profile gas block.
Each Pinned Gas Block Barrel comes with the pin, as well as a gas block. Gas blocks are hand-tightened to the barrel for shipping.

Faxon Firearms barrels are the pinnacle of value. 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
    Faxon barrels

    Posted by Eric Brockman on Mar 18th 2024

    What can I say that we don’t already know. It’s a Faxon barrel. Top notch, never disappointing barrels. I only wish they made more options or maybe even some customized options.

  • 5
    light weight EDC

    Posted by Robert Head on Apr 24th 2023

    This barrel provides excellent accuracy for medium ranges and it's light weight aids handling and carrying.

  • 5
    16" pencil profile WITH pinned gas block? Yes please!

    Posted by Joe Szo on Apr 20th 2021

    Wait wait wait...a 16" pencil profile barrel with a pinned gas block at such a great price from Faxon? Wasn't even a hesitation with how quickly these go. I picked up one, and now I HAVE to build another upper!