The Diamondback Firearms DB15 Obsidian Series is a 6mm ARC semi-automatic rifle built around forged 7075-T6 aluminum receivers and a reliable mid-length direct-impingement gas system. Its 18-inch medium-profile 4150 chrome moly vanadium barrel features a 1:7.5 right-hand twist, black nitride treatment, and a DB Obsidian muzzle brake attached to 5/8x24 threads. A 15-inch M-LOK handguard provides versatile accessory mounting with a full Picatinny rail and quick-detach sling mounts. Magpul MOE K2 and CTR furniture support comfortable handling, while the flattop receiver is ready for a separately selected optic. The rifle includes one 26-round metal magazine.

Key features

• 6mm ARC chambering offers a capable intermediate rifle cartridge for target shooting and hunting applications.
• 18-inch medium-profile barrel uses a 1:7.5 right-hand twist and black nitride finish.
• Mid-length direct-impingement gas system supports balanced cycling and handling.
• Forged 7075-T6 aluminum upper and lower receivers provide a durable lightweight foundation.
• 15-inch M-LOK handguard includes a full Picatinny rail, anti-rotation design, and QD sling mounts.
• Magpul MOE K2 grip and CTR carbine stock improve control and adjustability.

The Diamondback DB15 Obsidian Series combines a practical AR-15 configuration with 6mm ARC performance and flexible accessory mounting.