This is a Diamondback AR-10 rifle called the DB10 chambered in .308 win. This model has an 18 inch fluted stainless steel barrel.
SPECS:
Model: DB10ELB
Caliber: .308 Winchester
Barrel: Diamondback Barrels 18”, Mid-Length, Medium, 416-R Stainless Steel, Fluted
Twist Rate: 1:10 RH
Gas System: Mid-Length Gas System
Bolt Carrier: AR10 Carrier w/ Multi-Cal DPMS Bolt, High Pressure Firing Pin
Handguard: Diamondback Aluminum 15” Keymod Rail
Trigger Group: Mil-Spec
Pistol Grip: Hexmag Grip
Stock: Adaptive Tactical Adjustable Stock (Ex Performance)
Mag:1- 20 round PMAG or 2- 20 round aluminum mags
Muzzle Brake: DB 30 Cal 5/8 x 24 Brake, 4140 Steel, Black Oxide Coated
Weight: 8 lbs 7.5 oz.
Overall Length (Stock Collapsed): 35.75”
Overall Length (Stock Expanded): 39”