Open Box Dealer Demo JP Enterprises Supermatch Barrel With Headspaced Jp Enhanced Bolt 6.5 Grendel 22in Black JPSM6.5G-22M8R-BT. 5 Grendel: Manufacturer: JP Enterprises Finish: Machined Stainless Fabric/Material: 416R Stainless Caliber: 6.5mm Grendel Gas System Length: Rifle Length Barrel Twist Rate: 1-8 Firearms Threads Per Inch: 5/8x24 Features of JP Enterprises Supermatch Barrel With Headspaced Jp Enhanced Bolt 6.5 Grendel Includes a JP EnhancedBolt individually head-spaced to the barrel for flawless fit and function. Chamber: 6.5 Grendel Contour: .650 under hand guard/.740 in front of gas block Package Contents: JP Enterprises Supermatch Barrel With Headspaced Jp Enhanced Bolt 6.5 Grendel JP Enterprises JPSM6.5G-22M8R-BT: Supermatch Barrel With Headspaced Jp Enhanced Bolt 6.5 Grendel 22in Black