The One Horse OH-15 is an AR-style rifle chambered in .300 AAC Blackout with a 16-inch threaded barrel and a 1:8 twist. It ships with a black Picatinny-rail receiver, an M-Lok handguard, and an A2 flash hider on the muzzle. The rifle has a semi-auto action, weighs 7.14 lbs, and comes with 30-round magazines and no factory-installed sights. 
 

Key Specifications 

• Brand: One Horse LLC 
• Model: OH-15 
• Caliber: .300 AAC Blackout 
• Action: Semi Auto 
• Capacity: 30+1 
• Barrel Length: 16" 
• Weight: 7.14 lbs 
• Finish: Black 
   

Detailed Features 

• 16-inch threaded barrel (5/8x24) with an A2 flash hider and a 1:8 twist 
• M-Lok handguard over a Picatinny-rail receiver for mounting optics and accessories 
• M4 6-position stock and A2 pistol grip round out the furniture 
• Black A2-style grip and black barrel and receiver finish for a consistent look 
• Ships with 30-round magazines and relies on optics or aftermarket sights since none are included from the factory

One Horse is a newer name in the AR-pattern space, and owners of the OH-15 in .300 Blackout tend to compare it against more established budget-tier ARs. Feedback on fit and function is generally positive, with the threaded barrel and flash hider running reliably out of the box.

Handling-wise, the M-Lok handguard and 6-position stock make the OH-15 easy to set up for a range of body types and accessory choices. Some owners note the A2 grip is a bit dated compared to more ergonomic aftermarket options, though it is a simple swap on an AR-pattern lower.

Because One Horse is a smaller manufacturer, some buyers mention doing more of their own research before purchase compared to picking up a rifle from a bigger-name brand. Those who already own other AR-pattern rifles find the OH-15 straightforward to maintain and accessorize with standard AR parts.