Heckler & Koch MR556 A4 5.56 NATO

The Heckler & Koch MR556 A4 is designed as a commercial variant of the HK416 platform, built for reliable performance in range, training, and general sporting use. Its short-stroke gas piston system reduces fouling in the action and supports sustained operation with less internal wear.

The MR556 A4 is constructed with a threaded 16.5-inch barrel, a slim M-LOK handguard, and a six-position synthetic stock to support comfortable handling and modular accessory mounting. The rifle includes a Picatinny rail, fully ambidextrous controls, and a collapsible HK416-style grip for familiar ergonomics.

Key Specifications

• The caliber is .223 Rem/5.56 NATO.
• The barrel length is 16.5 inches.
• The overall length is 36.5 inches.
• The action is semi-automatic.
• The barrel type is threaded.
• The handguard type is M-LOK with ambidextrous QD cups.
• The stock material is synthetic and the stock is a 6-position collapsible design.
• The rifle uses a short-stroke gas piston operating system.
• The rate of twist is 1:7.
• The rifle accepts a detachable magazine.

The MR556 A4 combines piston-driven reliability with modern modular features and fully ambidextrous controls, making it a capable modern sporting rifle option for those evaluating Heckler & Koch firearms. For more information on availability, search for the Heckler & Koch MR556 A4 5.56 NATO rifle for sale online.