The Diamondback DB15 is an AR-pattern pistol chambered in 338 ARC with a 10.5-inch barrel and a black anodized finish. It ships with an SB Tactical SBA5 brace, an M-LOK handguard, and a Magpul grip. The magazine capacity is 26 rounds. 
 

Key Specifications 

• Brand: Diamondback 
• Model: DB15 
• Caliber: 338 ARC 
• Action: Semi Auto 
• Capacity: 26+1 
• Barrel Length: 10.5 in 
• Color/Finish: Black Anodized 
   

Detailed Features 

• 10.5-inch barrel in a compact AR pistol configuration; transfer of this short-barreled configuration requires additional federal paperwork 
• SB Tactical SBA5 stabilizing brace included 
• M-LOK handguard for accessory mounting 
• Magpul grip 
• Black anodized receiver finish

Owners of the DB15 in 338 ARC tend to cite the caliber choice as the main draw: the cartridge delivers more energy out of a short barrel than a standard 5.56 build, and the 10.5-inch package keeps things compact. Reliability feedback is generally positive, with most owners reporting consistent cycling across a range of 338 ARC loads.

The brace configuration draws a mixed reaction. Some owners appreciate the SBA5 as a practical addition that makes the pistol easier to handle at distance, while others swap it out immediately for a different setup. The M-LOK rail earns consistent praise for giving plenty of room to run lights and other accessories without adding unnecessary bulk.

Value perception on the DB15 is split. Diamondback sits in the mid-tier price band and some owners feel the fit and finish reflects that, noting tooling marks and a trigger that has room for improvement. Others see it as a solid foundation for a build and accept the quality-to-cost trade-off without complaint.