The Diamondback DB15 is an AR-15 pattern pistol chambered in .300 AAC Blackout with a 10-inch barrel. It has a 30-round capacity, ships with an SBA5 brace, and has an M-LOK handguard. 
 

Key Specifications 

• Brand: Diamondback 
• Model: DB15 
• Caliber: .300 AAC Blackout 
• Action: Semi Auto 
• Capacity: 30 rounds 
• Barrel Length: 10 inches 
• Color/Finish: Black 
   

Detailed Features 

• AR-15 pattern pistol configuration 
• 10-inch barrel in .300 AAC Blackout 
• SBA5 pistol brace 
• M-LOK handguard 
• 30-round magazine

Owners of the DB15 in .300 AAC Blackout regularly note the caliber choice makes good use of the short 10-inch barrel, where .300 Blackout loses less velocity than traditional rifle cartridges. The M-LOK handguard gets practical marks for allowing clean accessory placement without adding unnecessary weight.

The SBA5 brace is a mixed topic. Some owners appreciate it as a functional option out of the box; others swap it for an aftermarket stock once they sort out their paperwork situation. A few owners flag fit and finish as adequate but not exceptional, particularly on the upper-to-lower receiver fit.

Diamondback is generally seen as a value-tier AR brand, and the DB15 sits in that position in the market. Owners who prioritize the .300 Blackout caliber and want a ready-to-run platform at a lower entry price tend to be satisfied. Those expecting match-grade components at this price point are often disappointed by the trigger and barrel crown quality.