The HK MR556 A4 AR-pattern pistol in 5.56 NATO with a 30+1 capacity and an 11-inch barrel (brand part no. 81001312) brings HK’s HK416-derived MR556 platform to a pistol configuration in a distinctive gray finish. HK builds the pistol with a 1-in-7-inch rifling twist suited to a wide range of 5.56 NATO bullet weights, and the semi-auto action feeds from a 30-round magazine. Among large-format AR-pattern semi-auto handguns, this MR556 A4 configuration favors shooters who want HK’s proven piston-driven AR platform in a compact, brace-ready pistol build.

Key Specifications

• Chambered in 5.56 NATO/.223 Remington.
• Capacity of 30+1 rounds.
• The barrel measures 11 inches, with a 1-in-7-inch rifling twist.
• The finish is gray.
• The action is semi-auto, built on HK’s MR556 platform.
• The sights are No Sights.
• Ships with one 30-round magazine.
• Shipping weight of approximately 11.4 pounds.
• The overall length is approximately 26.5 inches.

Frequently Asked Questions

Is this an AR-pattern pistol? Yes, it’s built on HK’s MR556 platform with an 11-inch barrel and no stock.

What rifling twist does this barrel use? A 1-in-7-inch twist, suited to a wide range of 5.56 NATO bullet weights.

Buy the HK MR556 A4 AR-Pattern Pistol

HK’s proven piston-driven AR platform in a compact pistol build is exactly what this MR556 A4 delivers. Order it from our Lubbock, Texas gun shop for fast, insured shipping to your FFL.