Diamondback DB15 Combo Pistol Kit Features The DB15 Combo Pistol Kit includes an 8 .300 Blackout complete upper alongside the standard 10 5.56 NATO configuration letting shooters swap between calibers on the same lower receiver without purchasing a second complete pistol. Both barrels are constructed from 4150 chrome moly steel with a 1:8 twist rate threaded to accept an A2 flash hider or other muzzle device. The carbine-length gas system and direct impingement operating system provide reliable cycling across both calibers. For shooters who want caliber flexibility without buying two separate pistols the DB15 Combo Pistol Kit delivers that versatility on one lower. Finished throughout in OD Green the kit includes MOE grips and a manual safety for straightforward familiar AR ergonomics. The A3 flattop upper provides a continuous Picatinny rail for mounting optics on either configuration and the 9 inch Diamondback M-LOK handguard offers ample space for lights lasers and other accessories. The kit ships with two magazines giving shooters ample capacity to run either upper right out of the box. For shooters who want a distinctive OD Green combo pistol with genuine multi-caliber flexibility the Diamondback DB15 Combo Pistol Kit is available now at GrabAGun. Diamondback DB15 Combo Pistol Kit Specifications Manufacturer: Diamondback Model: DB15 Combo Pistol Kit Type: AR-Style Pistol Combo Kit Caliber: 5.56 NATO / .300 Blackout Capacity: 30+1 Barrel Length: 10 in (5.56 NATO) 8 in (.300 Blackout) Barrel Material: 4150 Chrome Moly Barrel Twist: 1-8 Barrel Configuration: Single Threaded Barrel: Yes Rifled Barrel: Yes Muzzle: A2 Flash Hider Gas System Length: Carbine Operating System: Direct Impingement Frame Material: Forged 7075 T6 Aluminum Frame Finish: OD Green Finish: OD Green Scope Base: A3 Flattop Forend Rail: 9 in Diamondback M-LOK Grips: MOE Trigger: Mil-Spec Trigger Guard: Standard Safety: Manual Safety Magazine Type: Polymer AR Style Magazine Magazine Count: 2 Overall Length: 26.5 in Weight: 6.65 lbs Available At: GrabAGun