One Horse 10.5in .300 Blackout AR15 Barrel, 1:7 Twist

The One Horse 10.5in .300 Blackout AR15 Barrel (part no. OHBR06) is a bare replacement or build barrel chambered in .300 Blackout, a cartridge purpose-built for short-barreled AR15s. One Horse cuts this barrel with a 1:7 twist rate, fast enough to stabilize both lighter supersonic loads and heavier subsonic .300 Blackout ammunition.

Key Specifications

• Chambered in .300 Blackout, a cartridge designed to perform well out of short AR15 barrels.
• Cut to 10.5 inches, a common length for short-barreled pistol and registered SBR builds.
• Rifled at a 1:7 twist rate, fast enough to stabilize both supersonic and heavier subsonic .300 Blackout loads.
• Ships at approximately 1.3 lb, typical for a barrel of this length.

Frequently Asked Questions

Will this barrel stabilize subsonic .300 Blackout ammo? Yes, the 1:7 twist is fast enough to stabilize both supersonic and heavier subsonic loads.

Is a barrel this short legal to buy? Yes. A bare barrel, or a complete upper with no lower attached, is not itself a regulated firearm under the NFA. It only becomes a regulated Short-Barreled Rifle if it’s built onto a rifle-configured lower with a shoulder stock at an overall barrel length under 16 inches without prior ATF approval; pairing it with a pistol lower/brace setup or an already-registered SBR avoids that issue.

Buy the One Horse 10.5in .300 Blackout AR15 Barrel

Order this 10.5-inch .300 Blackout barrel from One Horse. Ships fast from a Lubbock, TX gun shop. See our full AR15 barrels selection for more build options.