One Horse 10.5" .300 BLK SOCOM Pistol 1:8 M-LOK Complete Upper - OH-CU05

Discover the ultimate in compact firepower with the One Horse 10.5″ .300 BLK SOCOM Pistol 1:7 M-LOK Complete Upper. Engineered for tactical enthusiasts and home defenders seeking a reliable, versatile AR-15 upper, this assembly delivers exceptional performance in close-quarters scenarios. Chambered in .300 Blackout, it excels with both supersonic and subsonic ammunition, making it ideal for suppressed pistol builds where maneuverability and quiet operation are paramount.

Key Features

• 10.5″ SOCOM Barrel: Crafted from durable 4150 steel with a nitride/Melonite finish for superior corrosion resistance and longevity. The Government/SOCOM profile ensures balanced weight and heat dissipation during extended sessions.
• Pistol-Length Gas System: Optimized for reliable cycling with .300 BLK rounds, reducing recoil and enhancing control in dynamic shooting environments.
• 1:8 Twist Rate: Stabilizes a wide range of bullet weights, from 110-grain supersonic to 220-grain subsonic, promoting accuracy without over-stabilization.
• M-LOK Free-Float Handguard: 10-inch rail provides ample space for accessories like lights, lasers, or grips, while maintaining a lightweight, ergonomic design for swift handling.
• Includes BCG and Charging Handle: Mil-spec bolt carrier group and charging handle come pre-installed, allowing immediate drop-in compatibility with your AR-15 lower receiver.

Technical Specifications

• Caliber: .300 Blackout (300 BLK)
• Barrel Length: 10.5 inches
• Muzzle Threading: 5/8×24 for easy suppressor or muzzle device attachment
• Overall Length: Approximately 19 inches
• Weight: 54 ounces – compact yet robust for pistol configurations
• Material: 7075-T6 aluminum receiver with hard-coat anodizing

Why Choose This .300 BLK Complete Upper?

In a market flooded with options, the One Horse upper stands out by addressing common pain points like unreliable cycling in short-barrel setups and limited accessory mounting. Its pistol-length gas system minimizes gas blowback, especially when suppressed, while the M-LOK system offers modular customization without added bulk. Whether you’re building a home defense pistol or a truck gun, this upper provides precision-engineered reliability that boosts confidence in high-stakes situations. Users appreciate its smooth operation and compatibility with standard AR components, eliminating the hassle of piecemeal assembly.

Elevate your AR build today with the One Horse 10.5″ .300 BLK SOCOM Pistol Upper – the perfect blend of power, portability, and performance. Ready to install and dominate the range or field.

Frequently Asked Questions

Is this upper compatible with standard AR-15 lowers?
Yes, it features a mil-spec upper receiver that mates seamlessly with any mil-spec AR-15 lower, ensuring a straightforward build process.

Can I use this upper for suppressed shooting?
Absolutely. The 10.5″ barrel and pistol gas system pair excellently with suppressors, optimizing for subsonic .300 BLK loads to reduce noise and recoil effectively.

What ammunition performs best with the 1:8 twist?
The 1:8 twist handles 110-220 grain bullets optimally, supporting both supersonic for velocity and subsonic for quiet, suppressed applications without compromising accuracy.