Faxon Duty Series 20" Gunner, 5.56 NATO, Rifle-Length, 4150 QPQ Nitride AR-15 Barrel

(10 reviews)
Current Stock:

The Gunner profile is a blend of two of the best performing profiles of all time, Gov't and Pencil. Faxon's Gunner profile combines the durability of the Gov't profile with the weight savings and maneuverability of the Pencil profile. The Gunner profile brings the balance of the rifle back towards the shooter's body, limiting fatigue, and allowing for shooting, training, or hunting all day long.

Faxon Firearms barrels are the pinnacle of value. Manufactured in-house in Cincinnati, Ohio, Faxon 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 beginning of the manufacturing process.. 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 with precision PTG gauges

  • Barrel Material: 4150
  • Barrel Type: Button Rifled 
  • Barrel Caliber: 5.56 NATO
  • Barrel Twist: 1:8
  • Barrel Length: 20"
  • Barrel Profile: Gunner
  • Barrel Gas System: Rifle Length
  • Inside Finish: Nitride
  • Outside Finish: Nitride
  • Muzzle Thread: 1/2-28
  • Gas Block Diameter: .625"
  • Gas Block Journal Length: 1.9"
  • Barrel Extension: M4
  • Weight: 1.67 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:
20" - 24"


  • 5
    Faxon 20 inch 5.56 Gunner barrel

    Posted by Pat on Mar 5th 2023

    Purchased this barrel to save a bit of weight on New Frontier billet AR that I use primarily for coyote hunting. Shaved quite a bit off compared to the stainless heavy barrel that was on it prior. Accuracy is top notch for a lightweight profile barrel. Using Hornady Match 73 gr ELD, the worst group of the day was 1.25 moa and the best was right at .6 moa. Ran it out to 800 yards and had no trouble hitting an 8 inch gong at that distance. Absolutely phenomenal performance from a barrel in this weight range. Yes it does heat up quick but it also cools down very quick and Faxon has done an excellent job with stress relieving so the POI shift is minimal. Overall I can't recommend Faxon barrels enough.

  • 5
    Great Barrels

    Posted by Patrick C on Jan 5th 2023

    These are great barrels; we use them quite a bit for retro builds. Keep in mind front sight bases and barrels are drilled as a match set. Unlike a previous review suggests there would be zero purpose in cross slotting the barrel for a FSB. Every single FSB install is different. Plenty of companies out there will install a fsb for you. Reusing an old one is not the best practice.

  • 5
    excellent barrel

    Posted by Thomas T Tanita on May 10th 2022

    Very light weight, accurate and none of the whip and drift found in traditional pencil barrels

  • 5
    20" gunner barrel

    Posted by Bob Kotinek on Mar 16th 2022

    Assembled this barrel on a Aero Precision upper and was very pleased with accuracy . Sighted in at 25 yards and moved to 100 . Almost 3 rounds in 1 hole. I have been shooting 5.56 for 55 years and this barrel impressed an old gunner !

  • 4
    20” gunner barrel

    Posted by Sean Whitfield on Mar 15th 2022

    This is a very high quality barrel my only qualm with it is that there is no option for it to be slotted for an a frame sight post. My rifle I’m building is an m16a1 clone on the outside with Gucci parts on the inside and a Gucci barrel. The barrel was the one I chose as it had the pencil profile after the sight block so it would give the proper look. It matted up perfectly with my colt upper and when I got my colt sight block and on the barrel I realized that it was slotted which was a pain staking process to solve considering most gun smiths in my area were unwilling to spend the time drilling it. That being said once I found a smith willing to do the work I had no problem with it and the rifle shoots terrifically. That being said in short in my mind one of the only ways this barrel can be improved is by adding an option for slots should you want that with your build.

  • 5
    20" Gunner, 5.56

    Posted by Jeffrey Lower on Jul 10th 2019

    I've bought a pair of these and have been very impressed. My first barrel has roughly 9k rounds through it and its still as accurate as the 1st. They clean up easily enough. They've performed flawlessly for me and I see little sign of wear. I would like to see them bring the nickel-Teflon to the extension, or at least as an option, and do a side by side on feeding and cleaning with the Wylde barrels I have. These are a great barrels at a great price and they will not fail you.

  • 4
    great barrel

    Posted by Robert Biddy on Apr 13th 2017

    Faxon is a great company and one of the few that make melonine barrels, only wish they made a 1 in 9 twist for it though. Most people shoot the 55g federal rounds. if they would branch out to midwayusa they would own alot of the barrel market.

  • 5
    20" gunner barrel

    Posted by Lance on Jul 8th 2016

    Have not shot it yet. Finnish looks great and I expect it to make my ole SP1 more accurate.

  • 5
    Awesome service!!!!!

    Posted by C.H. on Feb 16th 2016

    Very happy with the barrel. Was interested in the gas block before I saw the deal with the barrel. Great quality barrel for the price!