Brownells Ar-308 308 Caliber Bolt Carrier Group Nitride

The Brownells AR-308 .308 Caliber Bolt Carrier Group in Black Nitride finish is a complete, ready-to-install BCG built for shooters running DPMS LR-308 pattern rifles. Whether you're assembling a precision .308 rifle from the ground up or replacing a worn carrier in an existing upper, this is a no-compromise part engineered to handle full-power rifle rounds with the same exacting standards Brownells applies to their M16-style carriers. The Black Nitride finish delivers exceptional resistance to wear and corrosion—and unlike traditional hard-chrome internal surfaces, Brownells forgoes the chrome here because Nitride actually outperforms it in hardness.

Built from the ground up for durability, the bolt is machined from robust 9310 steel, heat-treated and shot-peened to achieve superb hardness and fatigue resistance. The carrier itself is forged from hardened 8620 steel. Both critical components undergo magnetic particle inspection (MPI) during manufacturing to catch any microscopic flaws before they become premature failures downrange. The carrier features forward assist notches for reliable charging, and the gas key is torqued and staked to spec. The extractor is pre-installed with a rubber insert and spring—ready to cycle .308, .243, 7mm-08, .338 Federal, .260 Remington, 6.5mm Creedmoor, or any .308 Winchester-derived cartridge your rifle chamber demands.

This is a complete bolt carrier group—everything arrives installed and ready: firing pin, firing pin retaining pin, cam pin, gas rings, gas key, extractor, and ejector. Drop it into your DPMS LR-308 pattern upper receiver and go to work. Just note: this BCG is not compatible with Armalite rifles, which use a different pattern.

Key Features

• Complete bolt carrier group with all sub-components installed and ready to function
• Black Nitride finish for superior wear and corrosion resistance
• 9310 steel bolt, heat-treated and shot-peened for hardness and reliability
• 8620 steel carrier with forward assist notches
• Magnetic particle inspected (MPI) for hidden flaws
• Extractor pre-installed with rubber insert and spring
• Gas key torqued and staked to specification
• Compatible with .308 Win and .308-based cartridges (.243, 7mm-08, .338 Federal, .260 Rem, 6.5mm Creedmoor, and others)

Specifications

Frequently Asked Questions

What rifles will this bolt carrier group fit?

The Brownells AR-308 BCG is designed for DPMS LR-308 pattern rifles. It is not compatible with Armalite rifles. If your upper receiver uses the DPMS pattern, this BCG will function in your .308 rifle.

What cartridges can I shoot through this bolt carrier group?

This BCG is built for .308 Winchester and calibers based on the .308 cartridge, including .243, 7mm-08, .338 Federal, .260 Remington, and 6.5mm Creedmoor. Always confirm your specific rifle chamber before purchasing ammunition.

Does it come fully assembled?

Yes. The bolt carrier group arrives complete with all sub-components installed: firing pin, firing pin retaining pin, cam pin, gas rings, gas key, extractor, and ejector. You can install it directly into your upper receiver.

Why is Black Nitride used instead of hard chrome?

Brownells chose Black Nitride finish because it is actually harder than traditional industrial hard chrome plating, delivering superior wear resistance. This is why the carrier interior is not hard-chromed—the Nitride finish alone exceeds chrome performance.