H&K MR556 A4 5.56x45mm 11″ Threaded Barrel 30+1

About this product

The Heckler & Koch MR556 A4 (HK 81001201) is a semi-automatic 5.56x45mm rifle built around a short-stroke gas piston operating system. The 11″ threaded barrel and a 30+1 capacity magazine make it suitable for a range of field and range applications. An adjustable gas regulator allows tuning for suppressed or unsuppressed operation. Fully ambidextrous controls, a slimmer profile, and reduced fouling enhance reliability and reduce maintenance needs.

Key Specifications

• The caliber is .223 REM/5.56 NATO.
• The action is Semi-Auto.
• The barrel measures 11″ and is threaded.
• The magazine capacity is 30 + 1.
• The weight is 6.61 lbs.
• The overall length is 26.50″.
• The handguard features M-LOK.
• The receiver finish is Patriot Brown.
• The stock material and finish are Black Synthetic.
• Controls include a Ambidextrous Safety Lever.

Built for dependable operation and low maintenance, the MR556 A4 is well suited for serious range use, duty applications, and precision-focused shooters who value piston-driven reliability and modular ergonomics. Its adjustable gas system and ambidextrous controls provide practical adaptability across configurations and operating conditions.