Faxon Firearms Gunner Duty Series 5.56 Nato 12.5" Black Nitride 4150 Cmv

The Faxon Firearms Gunner Duty Series 5.56 NATO 12.5" barrel is a short-barrel rifle component engineered for shooters who demand both reliability and shootability in a compact platform. Built on Faxon's proprietary Gunner profile—a hybrid design that merges the proven durability of a government profile with the weight and handling benefits of a pencil profile—this barrel delivers the kind of balance you need whether you're training, hunting, or running drills at the range. The 12.5" length makes it ideal for AR-15 builds where maneuverability and control matter, and Faxon's refined profile design shifts the rifle's balance point closer to your body, reducing shooter fatigue over long sessions.

This is a Faxon barrel through and through, which means it's manufactured in-house in Cincinnati, Ohio, with the kind of process discipline that separates quality barrels from commodity parts. The barrel is fully stress relieved and air-gauge tested during manufacturing, then finished inside and out with salt bath nitride for corrosion resistance and durability. The 11-degree target crown ensures consistent accuracy regardless of how you mount a suppressor or muzzle device. Every barrel is individually headspace-checked with precision PTG gauges—a step many manufacturers skip.

The Gunner profile itself is worth understanding: it's not a government profile, and it's not a pencil barrel. Instead, Faxon engineered a sweet spot that gives you the strength you need for hard use without the weight penalty of a heavier contour. Paired with the 1:8 twist rate and button rifling, this 5.56 NATO barrel stabilizes modern ammunition reliably and prints accurate groups. The 1/2x28 muzzle threading is standard for 5.56 hosts, so suppressor or flash hider selection is straightforward.

If you're building or upgrading a short-barreled rifle and want a barrel that balances shootability, durability, and value, the Faxon Gunner Duty Series delivers on all three fronts.

Key Features

• Proprietary Gunner profile combines government profile durability with pencil barrel maneuverability and weight savings
• Reduces rifle balance point toward the shooter for less fatigue during extended shooting sessions
• Manufactured in-house in Cincinnati, Ohio with full stress relief and air-gauge testing
• Salt bath nitride finish inside and out for corrosion and wear resistance
• 11-degree target crown for consistent accuracy and clean suppressor mounting
• Every barrel individually headspace-checked with precision PTG gauges
• Button rifled 4150 CMV steel for reliability and accuracy

Specifications

Frequently Asked Questions

What is the Gunner profile, and how is it different from standard AR-15 barrels?

The Gunner profile is Faxon's hybrid design that combines the durability of a government profile with the weight savings and handling advantage of a pencil profile. The result is a barrel that reduces overall rifle weight and brings the balance point closer to the shooter's body, decreasing fatigue during long shooting sessions, while maintaining the strength you need for reliable, hard use.

What ammunition does this barrel stabilize?

With a 1:8 twist rate, this 5.56 NATO barrel reliably stabilizes modern 5.56 ammunition. The 1:8 twist is the current military standard and handles a wide range of bullet weights commonly used in training, hunting, and duty applications.

Is the muzzle threaded for suppressors?

Yes. The barrel features 1/2x28 muzzle threading, the standard for 5.56 NATO platforms. The 11-degree target crown ensures clean, accurate mounting for suppressors, flash hiders, or other muzzle devices.

What does "individually headspace-checked" mean, and why does it matter?

Each Faxon barrel is checked with precision PTG gauges to ensure correct headspace—the critical dimension that affects both safety and accuracy. This individual verification step is a sign of manufacturing quality and helps ensure the barrel will function reliably in your build.