The CMMG MK4 Upper Receiver is designed for 223 Remington/556NATO caliber, made from durable 7075 T6 AL billet aluminum, and finished with a sturdy cerakote in Armor Black. It ships with a dust cover and a forward assist assembly already installed.
Specs
| Model No. | CMMG55BA206-AB |
| Model | MK4 |
| Manufacturer | CMMG |
| Color | Black |
| Caliber | 223 Remington |
