CMMG Upper Receiver Assembly, Mk4/AR15, Forward Assist

Upper Receiver Assembly, Mk4/AR15, Forward Assist

Whether it’s the classic style or forward assist functionality that piques your interest, the Mk4 AR15 upper receiver assembly has been a staple in the CMMG® lineup. Available in seven different Cerakote finishes, this mil-spec workhorse has been proven over the years and makes a great base to build your next AR15 upper group.

Lifetime Quality Guarantee

We aim to please, that’s why every CMMG product is backed by our Lifetime Quality Guarantee against material and workmanship defects. Learn More.