Cmmg Bolt Carrier Group Mk3 308

The CMMG Bolt Carrier Group Mk3 308 is a complete replacement or upgrade component engineered specifically for .308 Winchester / 7.62×51mm NATO platform rifles. This precision bolt carrier group is designed for reliability in tactical rifle systems, making it suitable for various applications including precision shooting and law enforcement duty.

Constructed from 8620 steel with a durable phosphate finish, the carrier balances hardness and corrosion resistance in demanding field conditions. The bolt is made from 9310 steel, a high-strength alloy chosen for its ability to handle the pressure curve of the .308 cartridge. These material choices ensure consistent lockup and controlled gas operation across a range of ammunition loads.

This bolt carrier group is ideal for shooters looking for a drop-in replacement component or those assembling a complete rifle platform. The Mk3 308 is particularly suited for precision rifle builds and patrol rifles, where dependable function under varying conditions is essential. Weighing 1.31 lbs, it integrates seamlessly into standard .308 AR-pattern receivers without modification.