HK MR556 A4 5.56 NATO 11″ 30+1 Gray

The Heckler & Koch MR556 A4 chambered in .223 Rem/5.56 NATO features an 11" barrel and a gray Cerakote finish. It employs a short-stroke gas piston system with an HK416 upper receiver and an M-LOK handguard for modular accessory mounting. Controls and ergonomics are addressed with a fully ambidextrous lower and an HK enhanced grip for handling versatility.

Key Specifications

• The caliber is .223 REM/5.56 NATO.
• The barrel measures 11".
• The capacity is 30 + 1.
• The action is Semi-Auto.
• The finish is Gray Cerakote.
• The overall length is 26.5".
• The rate of twist is 1-in-7".
• The NFA thread pattern is 1/2x28.
• The receiver is described as Fully Ambidextrous Lower.
• The package includes 1 30 rd. magazine.

Compact and purpose-built, the MR556 A4 pairs HK’s piston operation and robust components in a short-barrel configuration for controllable handling and accessory flexibility. The threaded muzzle and M-LOK handguard accommodate a range of attachments while the ambidextrous controls and ergonomic grip support consistent operation. This configuration is suited for shooters who prioritize a durable, adaptable 5.56/.223 platform for range use and modular setups.