The HK 81001033 MR556 A4 5.56x45mm delivers Heckler & Koch’s proven HK416-style performance in a California-compliant, semi-automatic rifle. Built around a 16.5" cold hammer forged, threaded barrel and a short-stroke gas piston system, it keeps hot fouling out of the receiver for cleaner operation, longer service life, and more consistent reliability. A full-length Picatinny top rail, slim profile handguard, and black polymer stock and grip create a modern, optics-ready platform with fully ambidextrous controls.

This MR556 A4 configuration uses a 10+1 capacity and adjustable gas regulator, allowing shooters to tune the rifle for suppressed or unsuppressed use while staying within restrictive jurisdictions. With its 7.67 lb weight, 36.5" overall length, and smooth semi-auto action, it is well suited for range work, training, and general-purpose sporting use. The combination of precise German engineering and HK’s no-compromise design philosophy makes this rifle a refined choice for enthusiasts who value durability and consistency.

Key Features:

• Manufacturer: Heckler & Koch
• Model: MR556 A4 81001033
• Caliber: 5.56x45mm / .223 Remington
• Condition: New
• Action: Semi-Auto
• Barrel Length: 16.5"
• Number of Magazines: 1
• Capacity: 10+1
• Threaded Barrel: Yes
• What's In The Box: Rifle, 10-round magazine
• Weight: 7.67 lb
• Length: 36.5" overall