Diamondback DB15 .300 Blackout Semi-Auto Rifle - 16" Barrel, 10-Round, Black

The Diamondback DB15 .300 Blackout semi-auto rifle is built for shooters who want a compact, hard-hitting platform without the NFA hassle of a suppressor-ready setup. Chambered in .300 Blackout with a 16-inch free-float barrel and 1:8 twist rate, this rifle delivers the subsonic performance and ballistics that make .300 Blackout such a capable hunting and tactical round. The pistol-length gas system keeps the action smooth and reliable across a range of ammunition types, while the 10-round magazine capacity makes it practical for hunting or range days.

Built on a foundation of forged 7075 T-6 aluminum upper and lower receivers, the DB15 combines durability with reasonable weight. The barrel is Diamondback's own 4150 chrome-moly steel with black nitride finish—no threading, so you're working with what's on the gun. A mil-spec 8620 bolt carrier with magnetic particle inspection ensures consistency and longevity. The 12-inch M-LOK handguard gives you clean rail real estate for lights, lasers, or backup optics without unnecessary bulk, and the Thordsen Featureless Gen II stock keeps you compliant in restricted states while maintaining a solid cheek weld and ergonomics.

Whether you're hunting hogs, suppressed or unsuppressed, or running drills at an indoor range, the DB15 .300 Blackout delivers proven reliability in a package that won't break the bank or your shoulder. The free-float barrel supports accuracy, and the straightforward mil-spec internals mean parts support and aftermarket compatibility are never in question.

Key Features

• .300 Blackout caliber—ideal for hunting and close-quarters performance
• 16-inch free-float barrel for consistent accuracy
• 1:8 twist rate optimized for .300 Blackout ballistics
• Pistol-length gas system for reliability across ammunition types
• Forged 7075 T-6 aluminum receivers for strength and durability
• Black nitride barrel finish resists corrosion
• 12-inch M-LOK handguard for accessory mounting
• Mil-spec 8620 bolt carrier with magnetic particle inspection
• Thordsen Featureless Gen II stock for ergonomics and compliance
• Includes 10-round Magpul PMAG

Specifications

Frequently Asked Questions

What's included with the DB15 .300 Blackout?

The rifle comes with one 10-round Magpul PMAG. Additional magazines, optics, and accessories are sold separately.

Is the Thordsen stock featureless for California or other restricted states?

Yes, the Thordsen Featureless Gen II FRS-15 stock is designed for compliance in restricted-feature states. It maintains full ergonomics and cheek weld without adjustable features that trigger feature bans.

Can I suppress this .300 Blackout rifle?

The barrel does not have threading, so it is not set up for a suppressor in its current configuration. You would need to have a gunsmith add threading if you plan to run a suppressor.

What's the advantage of the 1:8 twist rate?

The 1:8 twist is optimized for .300 Blackout and stabilizes the range of bullet weights that caliber is known for, from subsonic rounds to supersonic hunting loads, without sacrificing accuracy.