9310 Steel Material Standard Charging Includes Bolt, Bolt Carrier, Extractor Pin, Firing Pin, Cam Pin Staked Gas Key .224 Valkyrie Caliber Black Nitride Finish Carrier Parkerized Finish Bolt BCA's Bolt carrier groups are MPI inspected. Perfect for your next .224 Valkyrie AR-15 build. Specifications: Brand Bear Creek ArsenalCaliber / Gauge .224 ValkyrieCarrier Style StandardPlatform AR-15 Bolt Finish ParkerizedBolt Material 9310 Steel Carrier Finish Black NitrideGas Key Staked Magnetic Particle Inspection Yes {{widget type="Magento\Cms\Block\Widget\Block" template="widget/static_block/default.phtml" block_id="42"}}