DPMS Bolt Carrier Group Features The DPMS Panther Arms Bolt Carrier Group starts with a bolt machined from mil-spec Carpenter 158 steel a material chosen specifically for its ability to withstand the high heat and pressure cycles generated by repeated firing. The bolt is shot peened to relieve stress and improve fatigue resistance then high pressure tested and magnetic particle inspected to catch any hidden flaws before it ships. This level of quality control gives shooters confidence that the bolt will hold up under sustained use whether at the range or in a duty capacity. The black phosphate exterior finish adds corrosion resistance while the chrome lined bore keeps the carrier running smoothly with minimal friction. The gas key is machined from bar stock and chrome lined for durability then secured with grade 8 fasteners that are staked according to mil-spec standards to prevent loosening under recoil. This attention to the gas key construction helps maintain reliable cycling over the life of the rifle reducing the chance of gas leakage or key failure. Compatible with both 5.56 NATO and .300 Blackout chamberings this BCG offers flexibility for shooters running multiple upper configurations on the same lower. Note that the BCG ships packed dry for shipping purposes giving it a dusty gray appearance that will turn black once lubricant is applied before use. DPMS Bolt Carrier Group Specifications Manufacturer: DPMS Model: Bolt Carrier Group Caliber: 5.56 / .300 AAC Blackout Color: Black Material: Steel Finish: Phosphate Compatible Hosts: AR-15 Available At: GrabAGun