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

(33 reviews)
Current Stock:
Adding to cart… The item has been added

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
    This barrel makes a poor shooter look like and Gold Medal Olympian

    Posted by David D. on Nov 9th 2016 on Nov 9th 2016

    I recently got a system from Faxon. It’s an AR15 which consisted of a 16” pencil barrel, their new flash hider/ compensator, the Holding Upper and lower, a Faxon bolt carrier assy and a Hyperfire trigger. I took it to the range today and shot 5 rounds through it to get it close, I was using a Nikon 3-12x42 power scope shooting at 100yards. I put up a target and took my first shot. Made a quick windage and elevation adjustment then fired 4 consecutive rounds. I had 2 bullseyes and 2 just off dead center. The grouping was 0.950”, the ammo was cheap 30 cent a round Winchester 5.556/.223 ammo in the white box from Field and Stream. I was just laying the gun on my range bag Imagine what a good shooter, using match ammo and on sand bags could do. I bet you would hold 1/2MOA Thanks Faxon!

  • 5
    16" PENCIL, 5.56 NATO, MID-LENGTH, 4150 QPQ

    Posted by AD on Jul 26th 2016

    Barrel head spacing was correct. Barrel length was correct. Muzzle threads were correct and crisp. Barrel extension was correct. Gas port was properly sized for mid-length gas system and located correctly. Finish was complete and nice. Notes: All in all this is a great barrel, super light, correct to specifications. The value of this barrel is also another great point. I have used more expensive barrels that have the same attention to detail and workmanship as this one. The barrel is surprisingly accurate for its weight and the reduced rigidity found in pencil barrels. would recommend for use.

  • 5
    wonderful barrel

    Posted by Unknown on Jul 8th 2016

    This barrel is everything I expected, finish is flawless, markings are sharp and clear, and the inside of the barrel was beautiful upon arrival. I just finished my first range day with this barrel and I couldn't be happier, it groups tighter than me when I shoot offhand, it does heat up quick but it is so skinny it is to be expected. I doubt I will ever look anywhere else to buy a barrel for myself in the future. Wonderful product

  • 5
    lightweight build

    Posted by jim from TX. on Jun 27th 2016

    Wanted to do a lightweight build, heard about Faxon Firearms pencil barrel and talked to friends who use them. I was not disappointed, used with BCM Kmr 15" forearm it turned out fabulous. My wife shot it after I sighted in irons and red dot. "Thanks for my new ar honey, it's so much lighter than mine"! Yes dear your welcome.

  • 5
    best barrel for the money

    Posted by Greg McComb owner Maximum Ammunition LLC on Jun 7th 2016

    I'm building a light weight rifle and the pencil barrel was what I needed. Faxon has the lightest pencil barrel at a great price. I'm very happy with my purchase.

  • 5
    Good barrel

    Posted by Matt on May 15th 2016

    So far I am impressed with this barrel. It is nice and light, exactly what I was looking for. Everything is a perfect fit when paired with the Faxon low profile gas block and gas tube. As far as accuracy: when in my untrained, hobbyist hands, I put 30 rounds of American Eagle 5.56 55gr FMJ all center mass at 100 yards with iron sights, good enough for me. I definitely recommend this product and will return to Faxon on future builds.

  • 5
    Excellent Barrel!

    Posted by BigGunner81 on May 2nd 2016

    I purchase this for a light weight AR-15 Rifle build, and this barrel is the lightest I've seen so far in the 16inch length with a mid-length gas system. The finish of the barrel is beautiful! it shoots nice and accurate as well. I will be creating a more detailed review for my youtube channel in the near future at youtube.com/BigGunner81 this barrel will also be featured in the his-n-her rifle build video series as well as the Washington State build of the 50 states of AR-15 project. Thank you again Faxon for making these awesome barrels!

  • 5
    Great seller!

    Posted by Brennan / Firearms 4 Less on Mar 11th 2016

    We've been selling the Faxon barrels for just a short time but we've already re-ordered several times. Our customers frequently comment how great the accuracy can be with such a lightweight barrel. Keep up the great work! Brennan www.firearms4less.com

  • 5
    Nice Lightweight Barrel

    Posted by BlueandCold on Feb 25th 2016

    Was going to buy a heavier barrel (16" Gunner) , but they were not in stock and got tired of waiting. Bought the 16" Pencil barrel and I like it fine. Have shot only 150 rounds or so through it at 50 yds (to sight in) and 100 yards. Seems to shoot as well as I can hold at 100 yards with iron sights. I plan to use this in some Run N Gun events and will probably be glad I got the lighter barrel. I have a free float handguard and one thing I have noticed is that if you push on the barrel at the end it will move/flex. The barrel is not so much bending as it is flexing at the barrel nut. (Barrel nut is torqued properly). However, with a free float handguard the barrel is isolated from external forces (except gravity) so the flex is not an issue. If you ever rested the end of the barrel on something it would shift your point of aim. So don't do that.