The Diamondback DB15 Obsidian is a 5.56 NATO AR-style pistol built around an 11.5-inch barrel and finished in OD Green Cerakote. It pairs a forged 7075-T6 aluminum upper and lower with an SB Tactical SBA5 adjustable brace, giving it a compact, maneuverable footprint. The package ships with a 30-round Magpul PMAG and an M-LOK handguard for mounting accessories. 
 

Key Specifications 

• Brand: Diamondback Firearms 
• Model: DB15 Obsidian (DB1984K101) 
• Caliber: 5.56 NATO 
• Action: Semi Auto 
• Capacity: 30+1 
• Barrel Length: 11.5" 
• Finish: OD Green Cerakote 
• Material: 7075-T6 Aluminum receiver set 
   

Detailed Features 

• 11.5-inch 4150 chrome moly vanadium barrel with a black nitride finish and 1:8 RH twist 
• 1/2x28 threaded muzzle fitted with a Diamondback Obsidian muzzle brake 
• 11-inch M-LOK free-float handguard with QD sling mounting points 
• A3 flattop forged upper receiver with a full-length Picatinny rail for optics 
• SB Tactical SBA5 brace with adjustable length of pull, plus a Magpul MOE K2 grip

Owners of the DB15 Obsidian generally describe the build as solid for the price point, with the 7075-T6 receiver set and nitride-finished barrel holding up well under regular range use. Some note that fit and finish on Diamondback's Cerakote work is consistent, though a few mention wanting to swap the factory trigger for an aftermarket unit early on.

As a braced AR pistol, the DB15 Obsidian draws praise for how compact and easy to maneuver it is compared to a full-size carbine, especially with the SBA5 brace collapsed. The M-LOK handguard leaves enough real estate for a light or foregrip without adding much bulk.

On value, buyers tend to see the Obsidian series as priced fairly against other OD Green AR pistols, and the M-LOK and Picatinny layout means most standard AR-15 parts and optics drop right on without issue.