Product Description The Spike&';s Tactical Bolt Carrier Group (BCG) is a critical upgrade or replacement component for AR-platform rifles, featuring a Nickel Boron (NiB) coating applied inside and out on the bolt, carrier, and gas key for enhanced lubricity and easier cleaning. Built from proven materials and manufactured to MIL-SPEC-style expectations, this BCG is designed for dependable cycling and long-term durability, and is finished with a laser-engraved ST spider logo for a distinct, authentic look. Product Highlights Nickel Boron coating inside and out (bolt, carrier, and gas key) for smooth operation and simplified maintenance Machined carrier and bolt construction using 8620 tool steel (carrier) and Carpenter 158 steel (bolt) Shrouded firing pin and properly staked, forged MIL-SPEC gas key with Grade 8 hardware Quality control features include High Pressure Testing (HPT) and Magnetic Particle Inspection (MPI) on the bolt Laser-engraved with the Spike&';s Tactical ST spider logo for quick identification Specs Brand: Spike&';s Tactical Product Type: Bolt Carrier Group (BCG) Caliber Compatibility: 5.56 NATO / .223 Remington / .300 AAC Blackout Finish/Coating: Nickel Boron (NiB), coated inside and out (bolt, carrier, gas key) Carrier Material: 8620 tool steel Bolt Material: Carpenter 158 steel Carrier Style: M16 / Full-Auto Gas Key: Forged MIL-SPEC, Grade 8 hardware, properly staked Testing: Bolt is HPT and MPI Marking: Laser engraved ST spider logo Manufacturer Part Number: ST5BG03 UPC: 855319005501 Disclaimer: We strive to provide accurate and up-to-date product descriptions, specifications, and images; however, errors or omissions may occasionally occur. We are not responsible for any inaccuracies or discrepancies in the content provided. If you notice anything incorrect or unclear, please contact us so we can correct it. When in doubt, we recommend verifying details directly with the product&&';;s manufacturer.