H&K MR556 A4 5.56x45mm 11″ Threaded, 10+1

The Heckler & Koch MR556 A4 is a compact, semi-automatic carbine chambered in .223 Rem/5.56 NATO designed for reliable operation with reduced maintenance. It employs a short-stroke gas piston system with an adjustable gas regulator to support both suppressed and unsuppressed use. Fully ambidextrous controls, a slimmer profile and lighter weight improve handling and manipulation in field and range settings.

Key Specifications

• The caliber is .223 REM/5.56 NATO.
• The action is Semi-Auto.
• The barrel measures 11".
• This model features a threaded barrel as specified in the model configuration.
• The operating system is a short-stroke gas piston.
• The gas regulator is adjustable for suppressed or unsuppressed operation.
• The capacity is 10 + 1.
• The stock is a Black Synthetic 6 Position configuration.
• The handguard is an M-LOK handguard.
• The listed weight is 6.61 lbs.

Engineered for reduced fouling and simplified maintenance, the MR556 A4 offers a compact, controllable platform for range, duty, and sporting applications. Its piston-driven action and adjustable gas system make it a practical choice for operators who prioritize durability, ambidextrous ergonomics, and configurable accessories.