Heckler & Koch MR556 A4, 5.56 NATO, 16.5" Barrel, 1-30rd Magazine, Rifle

The HK MR556 A4 is the commercial evolution of the legendary HK416 platform — a short-stroke gas-piston 5.56 NATO rifle built for operators and professionals who demand low-maintenance durability and battle-proven reliability. With a 16.5" barrel, adjustable gas regulator, and a 30-round magazine, the MR556 A4 pairs duty-grade ergonomics with piston-driven cleanliness so the action runs longer and requires less frequent service than direct-impingement alternatives. HK’s short-stroke piston system keeps hot carbon out of the receiver for improved longevity and easier maintenance, while the adjustable gas regulator lets the operator tune the rifle for suppressed or unsuppressed use. Fully ambidextrous controls, a slimmer, lighter profile, and precision manufacturing deliver a responsive, easy-to-manipulate rifle that excels in duty, patrol, and intensive training cycles. When you need “no compromise” performance, the MR556 A4 answers.

Specifications:

• Model: Heckler & Koch MR556 A4
• Caliber: 5.56 × 45mm NATO
• Barrel Length: 16.5"
• Action: Short-stroke gas piston with adjustable gas regulator
• Capacity: 1 × 30-round magazine included
• Features: Duty-grade construction, reduced receiver fouling vs DI systems, optics-ready top rail, robust service finish
• Use Case: Duty, patrol, intensive training, low-maintenance deployments