The One Horse 7.5" 300BLK Complete Upper Receiver brings compact .300 AAC Blackout performance to the AR-15 platform in a ready-to-run package. Built around a 7.5" medium-profile barrel with a 1:7 twist and 5/8x24 threaded muzzle, it is optimized for both subsonic and supersonic loads. A 7" M-Lok free-float handguard and nitride-finished bolt carrier group round out a durable, smooth-cycling upper designed to pin directly onto any mil-spec AR-15 lower.

This complete upper is well suited for AR pistols and short-barreled builds where maneuverability and efficient use of .300 Blackout shine. The free-float handguard offers ample space for lights and accessories, while the standard charging handle keeps operation familiar and straightforward. Whether you are setting up a range-focused pistol, a training carbine, or a compact general-purpose rifle, this upper reflects One Horse’s attention to reliable construction and thoughtful design.

Key Features:

• Manufacturer: One Horse
• Model: OH 7.5 300BLK Complete Upper Receiver
• Caliber: .300 AAC Blackout
• Barrel Length: 7.5"
• Barrel Profile: Medium
• Rate Of Twist: 1:7
• Muzzle Thread: 5/8x24
• Gas System: Pistol Length
• Handguard Length: 7"
• Handguard Type: M-Lok Free-Float
• Bolt Carrier Group: Nitride-Finished, Included
• Charging Handle: Standard, Included
• Compatibility: Mil-Spec AR-15 Lowers