Outerwild M16 5.56mm Bolt Carrier Group Gold. The titanium nitride coating provides a very slick surface that makes for easier cleaning and increases reliability. Properly built no corners cut. Specifications for Outerwild M16 5.56mm Bolt Carrier Group: Manufacturer: Outerwild Finish: Titanium Nitride Fabric/Material: Steel Carrier Material: 8620 Steel Bolt Material: 9310 Steel Caliber: 5.56mm Gun Model: M16 Hand: Right Package Contents: Outerwild M16 5.56mm Bolt Carrier Group What firearm models does the manufacturer say Outerwild M16 5.56mm Bolt Carrier Group is compatible with? The manufacturer suggests that Outerwild M16 5.56mm Bolt Carrier Group is compatible with M16Outerwild 2009-0703-001-O: M16 5.56mm Bolt Carrier Group Gold