H&K 51000384 MR556 Upper Receiver Kit 5.56mm for AR15/M16/M4

Experience unparalleled reliability and performance with the H&K 51000384 MR556 Upper Receiver Kit, meticulously designed for discerning marksmen and tactical professionals alike. Imagine confidently taking aim with a system that minimizes carbon fouling and malfunctions, thanks to its innovative piston and pusher rod technology. As you engage in action, feel the smooth mechanics operate flawlessly, delivering superior firing capabilities whether you're at the range or in a high-stakes environment. The MR556 is not merely an upgrade—it's an evolution in firearms technology that caters to both competitive shooters and law enforcement personnel who demand perfection in every shot.

Equipped with a host of advanced features, the MR556 Upper Receiver Kit allows retrofit capabilities to Mil-Spec AR-style rifles, transforming standard builds into a pinnacle of reliability. The suppressor-ready design offers concentric 1/2X28 threads, providing the ultimate convenience for those who prefer stealth in their shooting applications. Imagine enjoying the dynamic versatility of the adjustable gas regulator, tailoring your shooting experience for both suppressed and unsuppressed firing with ease. With superior ergonomics through the extended ambidextrous charging handle and a continuous Picatinny rail interface, customization and adaptability are at your fingertips, ensuring that you’re always ready for your next mission.

The cold hammer-forged match rifle barrel exemplifies precision craftsmanship, promoting accuracy with every pull of the trigger. Designed and assembled in the USA with both US and German components, this kit holds true to Heckler & Koch’s commitment to quality and durability. The robust M-LOK interface with integrated ambi QD cups means you can easily enhance your setup with accessories, ensuring you leverage every advantage during your target practice or combat scenarios. When you choose the MR556, you're investing not just in a part, but in a legacy of reliability established by the HK416—used by elite forces around the world.

In a world where every second counts and every shot matters, the MR556 Upper Receiver Kit stands as a testament to superior engineering and performance. Elevate your shooting experience and maximize your firearm's potential with a system that promises to redefine your expectations of rifle handling and endurance. Embrace the power of precision today with a kit designed for those who refuse to compromise on excellence.

Key Features

• 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

Technical Specifications

What's in the Box

• Complete Upper Receiver Assembly
• Barrel Assembly with Adjustable Gas Block
• Handguard with M-LOK Features
• Extended Ambidextrous Charging Handle

Compatibility & Requirements

• Compatible with Mil-Spec AR15/M16/M4 Lower Receivers
• Installation of Mil-Spec hammers required for non-HK lower receivers

Dimensions & Weight