JP Enterprises Stainless full mass tactical carrier with QPQ without buffer for 6.5 Grendel Black JPBC-2A 6.5G. The exterior bearing surfaces are hand polished. Features a 100percent increase in bearing surface for smoother operation and improved alignment with less wear on the upper receiver. Comes with the key installed and is milled from 416 Stainless Steel. Specifications for JP Enterprises Stainless Full Mass Tactical Carrier: Manufacturer: JP Enterprises Color: Black Finish: Black Fabric/Material: Steel Carrier Material: 8620 Steel Bolt Material: 9310 Steel Gun Make: AR Platform Gun Model: AR-15 Hand: Right Additional Features: with QPQ without buffer for 6.5 Grendel Features of JP Enterprises Enhanced Bolt Assembly Group: Stainless full mass tactical carrier with QPQ (without buffer) Package Contents: JP Enterprises Stainless Full Mass Tactical Carrier What firearm models does the manufacturer say JP Enterprises Stainless Full Mass Tactical Carrier is compatible with? The manufacturer says that JP Enterprises Stainless Full Mass Tactical Carrier is compatible with AR-15JP Enterprises JPBC-2A 6.5G: Stainless full mass tactical carrier with QPQ (without buffer) for 6.5 Grendel Black