AB Arms Pro 5.56 BCG Complete Nickel Boron Assembly Bolt, Silver
Ab arms Ab Pro 5.56 bolt carrier Group is built to Mil-Spec dimensions. The nickel Boron coated bolt, carrier, gas key and Cam pin needs virtually no Lube during use. The phosphate coated extractor has a surface finish that provides superior extraction during firing. The nickel Boron coated carrier has a tough as nails finish that drastically enhances wear characteristics and provides surface lubricity.