CMMG MK3 .308 LPK Lower Parts Kits

The CMMG MK3 .308 LPK Lower Parts Kit provides the essential small parts and springs needed to complete a .308 Winchester AR-platform receiver into a fully functional lower assembly. This kit is designed for gunsmiths and experienced builders who already possess a stripped lower receiver and seek a reliable, mil-spec compatible component set.

The MK3 platform represents CMMG's proven engineering across law enforcement and military applications, ensuring each part meets durability standards under sustained fire and variable field conditions. This lower parts kit includes trigger group components, hammer, sear, disconnector, springs, pins, and selector lever—all the internal mechanisms required for reliable fire control in .308 caliber rifles. Each component is engineered to manage the higher recoil impulse and bolt carrier mass inherent to full-power rifle cartridges.

Armorers and serious AR builders benefit most from this kit, as it eliminates the need to source individual components and guarantees dimensional compatibility within the .308 platform ecosystem. Installation requires basic gunsmithing knowledge and familiarity with AR assembly, making it suitable for those with experience in building or customizing firearms.