NEMO Arms AR-15 .223 Remington/ 5.56mm Bolt Carrier Group. The bolt carrier group is the heart of your rifle. Selecting the best construction and coatings will ensure that you have lasting reliability and accuracy. Specifications for NEMO AR-15 .223 Remington/5.56x45mm NATO Bolt Carrier Group: Manufacturer: NEMO Arms Color: Steel Finish: Nickel Boron Carrier Material: 8620 Steel Bolt Material: 9310 Steel Caliber: 5.56mm .223 Remington Gun Make: AR Platform Gun Model: AR-15 Gun Type: Rifle Features of NEMO AR-15 .223 Remington/5.56x45mm NATO Bolt Carrier Group Case hardened 8620 steel bolt carrier nickel boron coated ground surfaces to meet exacting dimensional and surface finish tolerances Case hardened 9310 steel bolt nickel boron coated magnetic particle inspected ground surfaces to meet exacting dimensional and surface finish tolerances Hard chrome plated and ground firing pin Nickel boron coated gas key staked 4130 steel NIB coated cam pin NIB coated extractor with spring rubber insert and o-ring support Forward assist serrations Package Contents: NEMO AR-15 .223 Remington/5.56x45mm NATO Bolt Carrier Group What firearm models does the manufacturer say NEMO AR-15 .223 Remington/5.56x45mm NATO Bolt Carrier Group is compatible with? The manufacturer says that NEMO AR-15 .223 Remington/5.56x45mm NATO Bolt Carrier Group is compatible with AR-15NEMO Arms NSP-SF-BCG: AR-15 .223 Remington/ 5.56mm Bolt Carrier Group