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
    16" PENCIL, 5.56 NATO, Mid-Length, 4150 QPQ

    Posted by Ralph Seifert on Aug 18th 2017

    I have built several "loaner uppers" to send out to gun writers to review our QRB takedown system. One writer planned a grouping test without telling use. I sent him the loaner that had just come back from a tester doing 60 round full auto drum dumps. The barrel still shot sub-MOA! Out of an abused pencil with barrel! Faxon Barrels is my go to choice for barrels.

  • 5
    16" Pencil Barrel

    Posted by Rob Goodkind on May 4th 2017

    This barrel is lightweight and extremely accurate. I have bought 7 of them so far and will continue to buy this model in the future.

  • 5
    light and accurate

    Posted by robert soria on Mar 10th 2017

    This is hands down the best light weight barrel on the market. Buy it...you won't be sorry you did.

  • 5
    The reviews are legit!

    Posted by John Schrader on Feb 13th 2017

    Purchased the pencil barrel a few weeks ago building a lightweight coyote night rig. Wanted it light because the night scope weighs 3 lbs. The rifle came out under 10 lbs with the scope.Used Hornady factory ammo 55gr vmax. Sighted it in at 100. entered the ballistic data in the scope. walked a self healing target out to a random distance. Hit the target with the range finder at 258 yards. set the range in the scope shot 3 rounds in a tad under an inch. I have much heavier barrels that can't do this.

  • 5
    great penicl barrel

    Posted by heisman01@hotmail.com on Feb 1st 2017

    Put this barrel on a skinny AR15 build, added a mlok MI G3 rail and it's insanely light up front. Shot great right out of the box.

  • 5
    Best barrel on the market today

    Posted by CTW AMMO on Jan 31st 2017

    Have used a lot of Faxon barrels especially there PENCIL PROFILE BARREL, which meet or exceeds all expectation for accuracy and quality will continue to build on all FAXON barrels

  • 5
    Great Barrel, Within 1/2 MOA Precision, Light Weight

    Posted by HHM, Pahrump, NV on Jan 30th 2017

    Used this Pencil Profile barrel plus the corresponding gas block and gas tube offered from Faxon on 4 builds by now - absolutely love them. This barrel is is the finishing touch of a 5.6 lbs. AR 15 build for my wife and "we" love it. Light weight, very precise and helps with the overall balance of her rifle. Very light upfront with most of the weight perfectly centered. I can definitely recommend this product

  • 5
    Super Light and Accurate!

    Posted by Jarrod Cook on Jan 12th 2017

    This is my second pencil profile barrel from Faxon, the first has 3,000+ rounds through it and still shoots 1 MOA. Be sure to follow the break in procedure. If you are building an ultralight AR, this barrel is perfect...

  • 5
    Fantastic Pencil Barrel

    Posted by Unknown on Nov 28th 2016

    I bought this barrel for a lightweight/home defense build (~6.5 lbs fully decked out). The fit and finish was great. The only think I wish is that there was an option to have the barrel dimpled for the gas block I also bought from Faxon, Please do this!!! Or if you'd sell a gas block jig so I can sweat a little less when I have to dimple the barrel myself. The end product I built is a great shooter and pretty accurate for what it is. No problems with any of the ammunition that I've used with it thus far. Definitely love this barrel and I'm looking forward to using more of Faxon's barrels in the future.