JP Enterprises Supermatch Barrel With Headspaced JP Enhanced Bolt, 6.5 Grendel. Twist: 1-8. Rifle-length gas system. Threading: 5/8x24. Finish: Machined Stainless. Material: 416R stainless. Contour: .650 under hand guard/.740 in front of gas block. Includes a JP Enhanced Bolt headspaced to the barrel for flawless fit and function. Chamber: 6.5 Grendel.