CMMG AR15 Mil-Spec Steel Barrel Nut | 55DA296

Overview of the CMMG AR15 Barrel Nut | 55DA296

When you are building or repairing an AR15, one component you cannot afford to get wrong is the barrel nut. It is the critical threaded interface that locks the barrel to the upper receiver, and without a factory-spec fit, the entire build is compromised before you pull the trigger.

The CMMG AR15 Barrel Nut (55DA296) is a factory-original, mil-spec steel part made entirely in the USA at CMMG's facility in Fayette, Missouri. Machined to precise tolerances and finished in black, it delivers the thread engagement and secure barrel retention that law enforcement armorers, military personnel, and serious civilian builders have come to rely on from CMMG.

Why builders and armorers choose the 55DA296:

• Factory-original mil-spec construction for consistent, repeatable fit every time
• Steel construction with black finish for durability under demanding conditions
• Broad compatibility with carbine, mid-length, and rifle-length AR15 configurations
• American made by one of the most trusted names in the AR platform

Whether you are swapping out a worn nut on a duty rifle or starting a fresh build from scratch, the 55DA296 is the dependable choice.

Key Features

• Mil-Spec Construction: Factory-original CMMG component machined to mil-spec tolerances for a precise, repeatable fit in any standard AR15 upper receiver.
• Steel Build with Black Finish: Made from durable steel with a black finish for long-lasting reliability under demanding field and duty conditions.
• M4 Handguard Compatible: Works with all standard AR15 upper receivers equipped with M4-style drop-in handguards, including carbine-length, mid-length, and rifle-length configurations.
• Multi-Caliber Support: Compatible with AR15 builds chambered in .223 Rem, 5.56x45mm, and .300 Blackout.
• Internally Threaded Design: Secure internal threading provides firm barrel retention with the fit and torque retention expected of mil-spec hardware.
• Made in the USA: Manufactured by CMMG in Fayette, Missouri, under the same strict quality standards used across their entire AR platform line.
• Professional Installation Recommended: CMMG recommends installation by a qualified, trained gunsmith to ensure correct torque and headspace verification.

Specifications

Compatibility

The CMMG 55DA296 barrel nut is designed for all standard AR15 upper receivers and works with the following setups:

• Handguard Styles: M4-style drop-in handguards in carbine-length, mid-length, and rifle-length configurations
• Calibers: .223 Rem, 5.56x45mm, and .300 Blackout
• Platform: Standard AR-15 upper receivers with standard mil-spec threading

Not compatible with:

• AR10, .308 Win, or LR-308 platforms, which use a different receiver size and threading standard
• Free-float handguard systems that require a proprietary barrel nut with non-standard threading or geometry

When in doubt, confirm your handguard type before ordering. The 55DA296 is the correct choice for any AR15 build using M4-style drop-in handguards.

Intended Users

The CMMG AR15 Barrel Nut (55DA296) is built for anyone who demands quality and consistency in their AR15 build or armorer work. It is well suited for:

Law enforcement armorers who maintain agency duty rifles and need factory-spec replacement parts they can trust shift after shift. Military personnel and veterans building or servicing AR15 platforms for training or personal use will appreciate the made-in-USA mil-spec quality. Competitive shooters constructing custom AR15 configurations for matches or training benefit from a part that fits right the first time. Civilian gun enthusiasts and DIY builders completing their own AR15 builds will find the 55DA296 a cost-effective factory-quality choice. Gunsmiths and armorers performing routine maintenance and customer service work can rely on this part for consistent, repeatable results on any standard AR15 upper.

What's Included

• 1 x CMMG AR15 Mil-Spec Barrel Nut (MPN: 55DA296)

Note: A standard AR15 armorer's wrench is required for proper installation and is sold separately.

Available at WCUniforms

WCUniforms is a law enforcement, military veteran, and EMT-owned specialty retailer focused on uniforms, tactical gear, and public safety equipment, serving officers, agents, armorers, and builders across the United States. Unlike generic online marketplaces, WCUniforms curates its catalog specifically for professionals who need gear that works without question. Unlike free-float or aftermarket barrel nut options that may require custom fitting, the CMMG 55DA296 is a direct mil-spec factory part that drops in without hassle. Shop with confidence at wcuniforms.com.