Rock River Arms 5.56 NATO 18" 21-Round Stainless Rifle

The Rock River Arms 5.56 NATO 18" 21-Round Stainless Rifle is purpose-built for shooters demanding accuracy, reliability, and flat-top modularity in a mid-length platform. Designed for tactical professionals, law enforcement, and serious civilian marksmen, this rifle delivers the precision expected from Rock River Arms' manufacturing standards while maintaining the ergonomic accessibility of the AR-15 platform. The 18-inch barrel strikes an optimal balance between velocity retention and maneuverability, making it suitable for both stationary and dynamic shooting scenarios.

The stainless steel construction provides superior corrosion resistance and longevity compared to standard chrome-moly barrels, critical for operators working in harsh environments or coastal regions. At 16.5 pounds, the rifle maintains manageable control without sacrificing durability—weight distribution remains balanced across the 40-inch overall length. The 21-round magazine capacity delivers effective follow-up shot capacity while maintaining round reliability and feed consistency across extended shooting sequences. The flat-top receiver accepts any MIL-STD-1913 Picatinny rail-mounted optic or accessory, allowing customization for mission-specific requirements without proprietary components.

Law enforcement tactical teams and military units benefit from Rock River Arms' quality control and proven reliability under stress testing, while civilian precision shooters appreciate the inherent accuracy of the stainless barrel profile. The rifle performs reliably with standard 5.56 NATO and compatible .223 Remington ammunition, functioning across the full range of commercially available loadings. Installation of optics, lights, or rail-mounted systems requires only standard AR-15 compatible accessories and a basic understanding of Picatinny mounting—no gunsmith work necessary. This rifle integrates seamlessly into existing AR platforms and is compatible with all standard AR-15 lower receivers and modern charging handles.