CMMG Mk3 .308 Fixed Stock Kit with A1 Receiver Extension

CMMG Mk3 .308 Fixed Stock Kit

This is a straightforward solution for builders completing a .308 lower receiver. The kit provides all the components necessary to finish your lower group when paired with a lower parts kit.

What's Included

• A1 Receiver Extension — The proven buffer tube design that has served rifle builders for decades
• .308 Rifle Buffer Assembly — Properly weighted for .308 Winchester recoil impulse
• .308 Rifle Action Spring — Matched to the buffer assembly for reliable cycling
• A1 Rifle Length Butt Stock — Fixed stock configuration with classic profile

Design Philosophy

CMMG has engineered this kit around the A1 platform, which remains the gold standard for reliability and simplicity. The fixed stock design eliminates unnecessary complexity while providing a solid shooting platform. The .308-specific buffer and spring ensure your rifle cycles properly with the heavier recoil of the larger cartridge.

This kit works seamlessly with standard .308 lower receivers and pairs with any compatible lower parts kit to create a complete, functional lower group ready for upper assembly.