Caliber: .308 Winchester / 7.62 x 51 NATO Action: Gas operated, piston driven semi-automatic Sights: Integrated modern optics scope rail and original iron sights Stock: American Walnut Finish: Manganese Phosphate Barrel Length: 19.25 modified USGI profile barrel Twist: 1-10 RH Grooves: 4 Overall Length: 41 Weight: 9 lbs Length of Pull: 13.2 Limited Lifetime Warranty