Lead & Steel ARC C158 Bolt Carrier Group - DLC - HP/MPI - 5.56 Why we like these: Where to start? We could say we love these because of the incredibly smooth and nearly indestructible DLC (Diamond Like Carbon) coating. We could say we love these because of the shot-peened and individually proof-tested... MSRP: Was: SALE: $174.49 Add to Cart