CMMG AR-15 Upper Group, Mk4 K, 5.56mm
The Mk4 K Upper Group includes the RKM11 KeyMod free floating hand guard. The barrel is a nitrided 4140 CrMo steel 12.5" barrel available in both 5.56x45mm and 300 AAC Blackout. Each Upper Group is covered by CMMG's lifetime quality guarantee.
Features and Specifications:
Manufacturer Number: 55BDF19
Barrel: 12.5" medium weight multi-role profile
Muzzle: A2 comp., threaded 1/2-28
Hand Guard: CMMG RKM11 KeyMod hand guard
Receiver: Forged 7075-T6 AL M4 type upper
Gas Port Location: Carbine
Installing this product will subject it to NFA laws and doing so without a license is a felony possession of a Class III firearm. Check your local laws.