H&K MR556 A4 5.56mm Pistol — 30-Round, Black

About this product

The Heckler & Koch MR556 A4 is an AR-style semi-automatic pistol offered in .223 REM / 5.56 NATO with an accessory-ready platform suitable for range use and defensive applications. It features a threaded barrel and an M-LOK handguard for mounting lights, grips and other accessories. Controls are fully ambidextrous and the pistol ships with one 30‑round magazine. The design incorporates HK’s commercial short-stroke gas piston features for reduced fouling in the action compared with direct-impingement designs.

Key Specifications

• Chambering is .223 REM / 5.56 NATO.
• Standard magazine capacity is 30 rounds.
• Action type is semi-automatic.
• Model designation is MR556 A4.
• Weight is listed as 6.6 lb.
• The pistol ships with one 30‑round magazine.
• Barrel configuration is described as threaded with a 1/2×28 thread pattern.
• Stock and furniture are black synthetic.
• Grip material is black polymer.
• Lower receiver is described as fully ambidextrous.

The MR556 A4 combines proven HK engineering and a feature set focused on usability and reliability: ambidextrous controls, an accessory-ready M-LOK fore-end and a threaded barrel make this platform adaptable for a variety of range and defensive roles. Supplied with a 30‑round magazine, it offers a ready-to-configure foundation for shooters seeking a high-quality AR-style pistol.

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