Our Stag 10 Left Handed QPQ Nitride Bolt Carrier Group is designed to work with any rifle, upper half, or barrel designed for left hand ejection in .308/6.5 Creedmoor. QPQ, or Quench polish quench, is a specialized type of nitrocarburizing case hardening that increases corrosion resistance. Compatible with Stag Upper Receivers.Specifications: BCG Caliber: .308/7.62x51/6.5MM CM Ejection Orientation: Left-Handed Ejection Coating: Black Nitride Bolt carrier material: 8620 steel Bolt: Right-Handed Bolt assembly Included parts: Bolt carrier, bolt assembly, cam pin, firing pin, and firing pin retaining pin Design: carrier with a shrouded firing pin Staking: Proper mil-spec staking of the gas key