The Faxon Firearms Duty Series barrel is a 20-inch, 5.56x45mm NATO barrel built for AR15/M16 rifles that need reach without excess weight (brand part no. 15A58R20NGQ). FAXON FIREARMS machines this Gunner-profile barrel to blend the durability of a Government contour with the weight savings of a Pencil contour, then button-rifles the bore and finishes it with nitride inside and out for corrosion resistance. An 11-degree target crown and full stress-relief process keep the barrel shooting accurately shot after shot, and the 1.9-inch gas block journal pairs with standard rifle-length gas blocks. It is a strong choice for a designated-marksman-style AR build or a long-range training rifle.

Key Specifications

• Chambered in 5.56x45mm NATO/.223 Remington, compatible with AR15/M16 platforms.
• 1-in-8 twist rate stabilizes a wide range of 5.56 bullet weights.
• 20-inch barrel length with a rifle-length gas system for a soft-shooting, accurate platform.
• Gunner profile blends the durability of a Government contour with the weight savings of a Pencil contour.
• Button-rifled bore for tight, consistent tolerances.
• Nitride finish inside and out resists corrosion and reduces fouling.
• 11-degree target crown protects the muzzle and supports accuracy.
• 1/2-28 threaded muzzle accepts standard 5.56 muzzle devices.
• 1.9-inch gas block journal fits standard rifle-length gas blocks.
• M4 feed ramp barrel extension for reliable feeding.

Frequently Asked Questions

What twist rate does this barrel use? A 1-in-8 twist, which stabilizes a broad range of 5.56/.223 bullet weights.

What thread pattern is on the muzzle? A standard 1/2-28 thread, compatible with most 5.56 muzzle devices.

Is this barrel chrome lined? No, it uses a nitride finish inside and out rather than chrome lining, which Faxon selected for corrosion resistance and accuracy.

Buy the Faxon Firearms Duty Series 20-Inch 5.56 NATO Barrel

Order this Duty Series barrel from our Lubbock, Texas gun shop and build a long-range-capable AR15/M16 rifle with a proven Gunner-profile design. Browse our full AR15 barrels lineup for more lengths and calibers. Ships fast from a Lubbock, TX gun shop.