HK MR556 A4 SBR - 11"

The HK MR556 A4 SBR is a short-barreled rifle designed with an 11-inch barrel and a reinforced system derived from Heckler & Koch’s proven AR-platform engineering. Built around a short-stroke gas piston operating system, the design helps prevent carbon fouling from entering the receiver, supporting consistent operation and reduced maintenance requirements.

The rifle features an adjustable gas regulator that allows users to configure the system for both suppressed and unsuppressed use. The MR556 A4 incorporates a strengthened upper assembly, precision barrel, and durable components suitable for a variety of professional and sporting applications.

Specifications

• Caliber: 5.56 × 45mm
• Overall Length: 27.9 in. – 31.7 in.
• Overall Height: 7.5 in.
• Barrel Length: 11 in.
• Weight (without magazine): 7.67 lb
• Barrel Profile: 6 lands and grooves
• Twist Rate: 1:7, right-hand twist