Rock River Arms MR556 A4 5.56 NATO 16.5" Rifle

Rock River Arms MR556 A4: American-Made Tactical Rifle

The Rock River Arms MR556 A4 represents a modern interpretation of the classic AR-15 platform, built to exacting standards by one of America's most respected rifle manufacturers.

Key Features

• Caliber: 5.56 NATO (also accepts .223 Remington)
• Barrel: 16.5" chrome-moly steel, 1:9" twist rate
• Capacity: 10+1 rounds
• Finish: Gray anodized aluminum receiver with gray furniture
• Operating System: Direct impingement (piston-less)
• Stock: Collapsible A4-style buttstock for adjustable length of pull
• Handguard: Picatinny rail system for accessory mounting

Why Choose the MR556 A4

Rock River Arms rifles are manufactured in Illinois using American labor and materials. The MR556 A4 combines proven AR-15 ergonomics with Rock River's quality control standards. The 16.5" barrel provides an excellent balance of velocity and maneuverability, making this rifle suitable for home defense, sport shooting, and tactical training.

The direct impingement system is time-tested and requires minimal maintenance compared to alternative designs. The gray finish resists corrosion and provides a professional appearance on the range or in the field.

Versatile Platform

The Picatinny rail system allows you to customize this rifle with optics, lights, and other accessories to suit your specific needs. Whether you're a competitive shooter, a defensive-minded citizen, or simply exploring the AR platform, the MR556 A4 delivers reliability and accuracy.