Heckler & Koch MR556 A4 Upper Receiver - 16.5"

Heckler & Koch, MR556 A4 Upper Receiver, 223 Remington/556NATO, 16.5" Barrel, Threaded 1/2X28, M-LOK Handguard, Anodized Finish, Black, Fits AR-15 Lower Receivers, Includes Bolt Carrier Group, Charging Handle, Buffer Weight and Buffer Spring.

• Suppressor-ready Concentric 1/2X28 Threads

• Adjustable Gas Regulator for Shooting Suppressed and Unsuppressed

• M-LOK Interface with Integral Ambi QD Cups

• Continuous Picatinny Rail Interface Between Upper Receiver and Handguard

• Extended, Ambidextrous

• Charging Handle with Dual Claws

• Match Rifle Cold Hammer-forged Barrel