The radical firearms 16" medium contour 6.5 grendel ar rifle uses mil-std upper and lower receivers along with a 15" rpr free-float rail system for increased accuracy, keeping your hands cool, and giving you plenty of room for accessories.It utilizes a 416r stainless steel barrel with a pepper pot brake and a mission first tactical minimalist stock.Metal Finish: Black Hardcoat Anodized/Stainless SteelAction: Semi-AutoCaliber: 6.5 GrendelBarrel Length: 16"Capacity: 15+1Safety: Manual ThumbStock Description: 6 Position MFT MinimalistMuzzle: Pepper Pot Muzzle BrakeReceiver Material: 7075-T6 AluminumSights: Optic ReadyBarrel Description: 416 Stainless SteelTwist: 1:9"Barrel Length Range: 16" to 16.99"Hand: RightStock Finish Group: BlackMetal Finish Group: Blued/Black