The Faxon Duty Series 10.5" Pencil Profile 5.56 NATO barrel delivers a lightweight, low-drag option for compact carbines without sacrificing durability or accuracy. Built from certified 4150 CMV, button-rifled with a 1:8 twist, and finished inside and out with black nitride, this 10.5" pencil-profile barrel is optimized for shooters who want compact handling and efficient performance.

Key Benefits

• Lightweight pencil profile: Lower overall weight (approx. 0.9 lb) for maneuverability and balance in compact carbines and AR pistols.
• Carbine gas reliability: 10.5" length tuned to carbine gas for better dwell and more consistent cycling than pistol-length barrels.
• Precision & durability: Fully stress relieved, air-gauge tested, magnetic particle inspected, and finished with an 11° target crown.
• Clean, corrosion-resistant finish: Black nitride inside and out for extended service life and easier maintenance.
• Standard compatibility: 1/2-28 muzzle threading and M4 extension are compatible with standard AR-15 components and muzzle devices.
• Compact gas block footprint: .625" gas block diameter on a 1.1" journal for low-profile gas block options and lightweight builds.

Specifications

Why Choose the Pencil Profile

The pencil profile is designed for shooters who want the lightest practical barrel without giving up the durability and QC expected from Faxon. With a slimmer contour and a .625" gas block journal, this 10.5" pencil barrel reduces weight and frontal area for faster handling and less fatigue on extended carry, while the carbine-length gas system helps deliver reliable cycling and easier tuning than pistol systems.

Installation & Compatibility

• Standard M4 barrel extension for compatibility with AR-15 bolts and uppers.
• Use a low-profile .625" gas block on the 1.1" journal for a flush, lightweight setup.
• 1/2-28 muzzle threads accept brakes, compensators, and direct-thread suppressor adapters; verify suppressor rating before use.
• Tune buffer/spring, gas tube length, and muzzle device to match your ammo and desired function for optimal reliability.

Frequently Asked Questions

Overview: Lightweight 10.5" Pencil Profile 5.56 Barrel for AR-15 Carbines

When you need a compact carbine that won’t slow you down, the Faxon Duty Series 10.5" Pencil Profile 5.56 NATO barrel delivers a high-value combination of low weight, service-grade durability, and repeatable accuracy. The pencil contour reduces mass at the front of the rifle for quicker transitions and better balance, making it a top choice for shooters who prioritize handling without compromising the structural integrity expected from a duty-series component.

This barrel begins with certified 4150 CMV bar stock and is button-rifled to a proven 1:8 twist, a versatile stabilization rate for 55–77 grain projectiles commonly used in defensive and match applications. Fully stress relieved to minimize point-of-impact shifts over time, each barrel receives a robust black nitride finish both inside and out to resist wear and corrosion while keeping bore maintenance straightforward. Attention to final details — including an 11° target crown, air-gauge testing, magnetic particle inspection, and individual headspace checks with hardened gauges — ensures the barrel leaves the shop ready to perform.

The 10.5" length paired with a carbine-length gas system provides improved dwell compared with pistol-length setups, which can lead to smoother cycling and easier tuning across a wider range of ammunition and muzzle devices. The slimmer .625" gas block journal (1.1" length) supports low-profile gas block options, while standard 1/2-28 muzzle threads accept a wide selection of brakes, compensators, and direct-thread suppressor adapters.

Whether building a lightweight patrol carbine, a balanced compact rifle, or a maneuverable AR pistol, the Faxon 10.5" pencil profile barrel balances handling and real-world durability. Backed by Faxon’s in-house manufacturing and stringent QC processes, it’s an excellent option for shooters seeking a performance-focused, low-mass barrel for 5.56 NATO applications.