The Diamondback DB15 Combo rifle system delivers an adaptable platform engineered for diverse operational requirements. This system includes two complete, distinct upper receiver assemblies, enabling immediate caliber conversion between 5.56x45mm NATO and .300 Blackout. This inherent versatility optimizes the platform for a range of applications, from precision target practice and general utility to specialized ballistic applications such as those required for specific hunting ammunition loads or personal defense scenarios.
Key Features
Multi-Caliber Adaptability
The primary utility of the DB15 Combo lies in its integrated multi-caliber capability. This package provides two dedicated upper receiver assemblies, allowing operators to seamlessly switch between 5.56x45mm NATO and .300 Blackout. This design facilitates efficient training protocols, mitigates logistical complexities associated with multiple standalone firearms, and permits rapid adaptation to varied engagement parameters or ammunition availability.
Engineered Reliability and Construction
Both upper receiver assemblies operate on a robust direct gas-impingement system, leveraging high-quality CNC machined components to ensure consistent cycling and long-term operational reliability. Each upper assembly is equipped with a 16-inch, 4140 chrome moly barrel, selected for its inherent durability and sustained accuracy potential. Muzzle blast and flash signature are managed by a standard A2 flash hider integrated onto each barrel.
Optimized User Interface and Accessory Integration
The rifle integrates a 12-inch M-LOK handguard on each upper assembly, providing secure, modular attachment points for essential firearm accessories such as weapon lights, laser aiming devices, or foregrips. This design facilitates effective accessory integration without compromising the rifle’s balance or handling characteristics. The platform further incorporates a Magpul MOE Carbine stock, offering adjustability and a stable shoulder interface, complemented by a Magpul MOE grip for enhanced weapon manipulation and ergonomic control.
Technical Specifications
- Caliber: 5.56x45mm NATO (with dedicated upper) / .300 Blackout (with dedicated upper)
- Operating System: Direct Gas-Impingement
- Barrel Length: 16 inches (on both upper receiver assemblies)
- Barrel Material: 4140 Chrome Moly
- Handguard: 12-inch M-LOK (on both upper receiver assemblies)
- Muzzle Device: A2 Flash Hider (on both upper receiver assemblies)
- Stock: Magpul MOE Carbine
- Grip: Magpul MOE
- Component Construction: CNC Machined









