The Diamondback Medium-Profile Barrel (brand part no. 300P105M50B8) is a 10.5-inch .300 AAC Blackout barrel built for AR-15 builds and finish-your-own projects. Cut with a 1:8-inch twist rate that stabilizes the full range of .300 Blackout bullet weights, from lightweight supersonic loads to heavier subsonic rounds, it’s finished in black Melonite for corrosion resistance and a hard, low-friction surface. The medium-profile contour balances weight and rigidity for a barrel that’s equally at home on a range gun or a duty build.

Key Specifications

• Chambered in .300 AAC Blackout.
• 10.5-inch barrel length.
• Medium-profile contour balances weight and rigidity.
• Cut with a 1:8-inch twist rate suited to both supersonic and subsonic loads.
• Finished in black Melonite for corrosion resistance and easy cleaning.
• Fits the AR-15 platform.

Frequently Asked Questions

Will this handle subsonic .300 Blackout loads? Yes, the 1:8-inch twist rate stabilizes the full range of .300 Blackout bullet weights, including heavier subsonic rounds.

What contour is this barrel? Medium profile, balancing weight and rigidity.

Buy the Diamondback Medium-Profile Barrel, .300 AAC Blackout, 10.5in

Finish your .300 Blackout AR-15 with a durable, ready-to-run barrel. Order it from our Diamondback Barrels lineup, part of our AR barrels selection, at our Lubbock, Texas gun shop as soon as it’s available to ship.