The AR-STONER 6.8 SPC, 224 Valkyrie Bolt Carrier Group is a great option for your next AR build. Chambered in the popular 6.8 SPC, 224 Valkyrie Caliber, this BCG is machined to strict military standards. State of the art magnetic particle testing ensures the assembly is free of imperfections and will function flawlessly. Featuring a staked gas key, the AR-STONER 6.8 SPC, 224 Valkyrie Bolt Carrier Group is drop-in ready.FeaturesChambered for 6.8 SPC, 224 ValkyrieMachined to Mil-Spec StandardsProperly Staked Gas KeyDrop-In Ready