One Horse Express | 5.56 NATO | 16" | Atrius FRS | 30rd AR-15 Rifle

The One Horse Express Rifle (MPN: AI01) is a factory-built 5.56 NATO AR-pattern rifle engineered around the Atrius Forced Reset Selector as a complete operating system. One Horse configures the selector, fire-control components, gas system, bolt carrier, buffer system, and receiver geometry together rather than treating the FRS as an aftermarket add-on.

The rifle uses a 16-inch SOCOM-profile barrel with a 1:8 twist, mid-length gas system, 1/2x28 muzzle threads, and A2 muzzle device. A 15-inch Express M-LOK handguard provides accessory space, while a Breek Warhammer Mod2 charging handle, THRiL RTG grip, and THRiL CCS stock complete the factory control package. The standard configuration includes one 30-round magazine.

Key Features & Capabilities

• Atrius FRS Equipped: Selector is installed and configured as part of the complete rifle system.
• 16-Inch SOCOM Barrel: 5.56 NATO barrel with 1:8 twist and mid-length gas system.
• 15-Inch M-LOK Handguard: Long accessory-ready rail with free working space around the barrel.
• Breek Warhammer Mod2: Ambidextrous charging handle included from the factory.
• THRiL Furniture: RTG grip and CCS stock complete the ergonomic package.

The AI01 is designed for buyers who want a complete factory-tuned Express rifle rather than assembling an FRS-capable AR from separate components. Browse AR-15 rifles or shop .223 / 5.56 ammunition.