CMMG 6mm ARC 16.10" AR-15 Barrel Sub-Assembly - 416R Stainless Steel, Black Nitride

Building a 6mm ARC AR-15 starts with the right barrel, and CMMG's 6mm ARC 16.10" AR-15 barrel sub-assembly delivers the foundation for a compact, efficient mid-range cartridge platform. Hornady's 6mm ARC is designed for shooters who want inherent accuracy and respectable velocity in a modern rifle format, and this CMMG barrel sub-assembly gives you a purpose-built component engineered specifically for that round. The 416R stainless steel construction with black nitride finish resists corrosion while keeping the weight reasonable—ideal for hunters, precision shooters, and rifle builders looking to maximize the potential of this intermediate cartridge without the footprint of a full-length magnum setup.

The 16.10" length strikes a practical balance for a 6mm ARC setup, offering maneuverability in the field or at the range without sacrificing the velocity window the cartridge is known for. CMMG's sub-assembly approach means you're getting a complete, ready-to-install barrel unit—no guesswork about bore quality or headspace. The black nitride finish provides a durable, low-maintenance surface that handles field use and regular cleaning without the fuss of bare stainless.

Whether you're assembling a precision rifle for medium-range hunting, building a versatile ranch rifle, or developing a 6mm ARC load-and-shoot rig, this barrel removes one of the critical uncertainties from the build process. Pair it with a compatible upper receiver, bolt carrier group, and handguard to complete your platform. 6mm ARC shooters appreciate the blend of ballistics and ergonomics this cartridge offers, and this barrel was built to make the most of it.

Key Features

• 16.10" barrel length optimized for 6mm ARC cartridge performance
• 416R stainless steel construction for durability and corrosion resistance
• Black nitride finish resists wear and simplifies maintenance
• Complete barrel sub-assembly—ready for upper receiver installation
• Purpose-built for Hornady's 6mm ARC platform

Specifications

Frequently Asked Questions

What is a barrel sub-assembly and what do I need to complete my 6mm ARC build?

A barrel sub-assembly is a ready-to-install barrel unit that mounts directly into a compatible AR-15 upper receiver. You'll also need a compatible upper receiver, bolt carrier group, charging handle, handguard, and lower receiver group to complete a functional rifle.

Will this 6mm ARC barrel work with standard AR-15 uppers and lowers?

This is a 6mm ARC-specific barrel and must be paired with a 6mm ARC–compatible upper receiver. Standard 5.56 NATO uppers will not work with this barrel, and this barrel is not compatible with other common AR-15 cartridges.

What's the advantage of the 416R stainless steel and black nitride finish?

416R stainless steel offers excellent corrosion resistance and durability, while the black nitride finish adds a hard, wear-resistant surface that requires minimal maintenance. This combination is field-proven for hunting and range use.

Is the 16.10" length suitable for hunting with 6mm ARC?

Yes. The 16.10" length balances maneuverability with the velocity characteristics that make 6mm ARC effective for medium-range hunting and precision shooting applications.