LWRCI DI Bolt Carrier Group 5.56 Nickel. These gains are achieved through LWRCI s design technology paired with industry-leading machining and material technology. The LWRCI improved carrier design is coupled with our new Advanced Combat Bolt (6.8 Only). The bolt features redesigned extractor springs bolt face and locking lugs. it is manufactured using a high technology alloy usually reserved for the manufacture of Formula 1 racing transmission components. In testing the LWRC International Advanced Direct Impingement Bolt Carrier Group exhibited remarkable performance running over 10000 rounds without stoppage or failure on a host weapon that was neither cleaned nor lubricated during the testing process. Specifications for LWRCI DI Bolt Carrier Group: Manufacturer: LWRCI Color: Nickel Caliber: 5.56mm Hand: Right Condition: New Package Contents: LWRCI DI Bolt Carrier Group LWRCI 200-0091A01: DI Bolt Carrier Group 5.56 Nickel