Heckler & Koch MR556 A4 Upper Receiver Kit 11.5"
Complete upper receiver assembly for AR-platform rifles. Features Heckler & Koch's proven piston system with pusher rod instead of direct impingement gas tube. Includes 11.5" barrel and soft case.
Heckler & Koch MR556 A4 Upper Receiver Kit
This complete upper receiver assembly transforms your AR-platform rifle with the same piston-driven system that has proven itself in military and law enforcement service worldwide.
Key Features
Piston-Driven Reliability
- Utilizes a short-stroke piston and pusher rod system instead of the traditional direct impingement gas tube
- Eliminates hot carbon fouling and waste gases from entering the receiver
- Dramatically reduces common malfunctions associated with direct impingement designs
- The same proven system found in the Heckler & Koch HK416
What's Included
- Complete upper receiver assembly
- 11.5" barrel chambered in 5.56mm
- Piston and pusher rod system
- Heckler & Koch soft case for transport and storage
Why This Matters
The piston system represents a fundamental improvement in AR-platform design. By keeping combustion gases out of the receiver, you get cleaner operation, reduced wear on internal components, and more reliable function in demanding conditions. This is the same technology that made the HK416 the choice of elite military and law enforcement units.
Simply remove your existing upper receiver and install this complete assembly on your compatible lower receiver. The retrofit is straightforward and requires no gunsmithing.
Features
- includes bolt and buffer
- m-lok handguard
