JP Enterprises Complete Bolt Carrier Group BCG including JPBC-3 6.5 Grendel low mass polished carrier and JPEB-6.5 Silver. These Bolt Carrier Groups by JP Enterprises are complete with a low mass carrier perfect for small frame 6.5 Grendel caliber rifles. The JP Enterprises 6.5 Grendel LMOS Bolt Carrier Group BCG is complete with a cam pin firing pin and a firing pin retainer. Choose the JP Enterprises Enhanced BCG for an advanced bolt carrier to increase the performance of your favorite rifle. Specifications for JP Enterprises Low Mass 6.5 Grendel Bolt Carrier Group (BCG): Manufacturer: JP Enterprises Fabric/Material: Steel Carrier Material: 8620 Steel Bolt Material: 9310 Steel Caliber: 6.5mm Grendel Hand: Right Package Contents: JP Enterprises Low Mass 6.5 Grendel Bolt Carrier Group J5-BCG-GRNF Cam pin Firing pin Firing pin retainer What firearm models does the manufacturer say JP Enterprises Low Mass 6.5 Grendel Bolt Carrier Group (BCG) is compatible with? The manufacturer says that JP Enterprises Low Mass 6.5 Grendel Bolt Carrier Group (BCG) is compatible with AR-15JP Enterprises JPBC-3SPA-6.5G: Complete bolt carrier group including JPBC-3 6.5 Grendel low mass polished carrier and JPEB-6.5 Silver