Heckler & Koch MR556 A4 Upper Receiver Kit 5.56 NATO 11" Black Anodized 51000385

Heckler & Koch MR556 A4 Upper Receiver Kit

The Heckler & Koch MR556 A4 Upper Receiver Kit is a compact, suppressor-ready assembly chambered in 5.56 NATO, designed for elite-level performance in tactical builds. It features an 11-inch match-grade cold hammer-forged barrel with 1/2x28 threading, a monolithic M-LOK handguard for accessory mounting, and an adjustable gas regulator for optimized function with or without suppressors. This complete upper fits standard AR-15 lowers, including a bolt carrier group and ambidextrous charging handle for immediate integration.

Delving deeper, the MR556 A4 Upper includes HK's short-stroke gas piston system for reliable operation in adverse conditions, with the adjustable gas block allowing seamless switching between suppressed and unsuppressed modes. The continuous Picatinny rail atop the handguard supports optics mounting, while integral ambidextrous QD sling cups enhance carry options. The anodized black finish provides corrosion resistance, ensuring longevity in harsh environments without added weight.

Tailored for CQB and suppressed applications, the Heckler & Koch MR556 A4 Upper Receiver Kit excels in close-quarters scenarios where maneuverability and quiet operation are critical, such as tactical training or home defense builds. Its precision engineering and modular design make it suitable for professionals seeking a high-performance upper that delivers consistent accuracy and adaptability across various setups.

Specifications