The San Tan Tactical Enhanced Bolt Carrier Group is precision-engineered for AR15 rifles chambered in 6mm ARC with a durable black nitride finish for superior corrosion resistance and reliability.San Tan Tactical Enhanced Bolt Carrier GroupDesigned for AR15 platform rifles6mm ARC caliber compatibilityBlack nitride finish for durability and corrosion resistanceEnhanced design for improved performanceMade with high-quality American materials and machineryBuilt with San Tan Tactical's commitment to American manufacturing excellence this enhanced BCG delivers the reliability and performance that shooters demand for their 6mm ARC AR15 builds.