The Lantac Full Auto Bolt Carrier Group .223/5.56 is machined from 8620 steel with a QPQ (Quench Polish Quench) nitride coated black finish. This BCG features shrouded forward-facing gas ports that allows the system to run with a smoother energy pulse. The tail of the carrier has a flared boss helping improve the lock position with the upper and increasing accuracy.The included Lantac CP-R360 domed head cam pin is machined from stainless steel and hardened for extra strength. The unique, domed style head is designed to curve away from the receiver's internal surface and help reduce wear. The flat face on the dome head allows it to be inserted the .223 / 5.56 bolt carrier without removing the gas key.Features: .223/5.56 NATO QPQ Nitride finish Forward porting Full auto and semi-auto compatible CP-R360 Cam Pin MPI Carpenter 158 Bolt, Shot Peened, Hard Turned/Ground Made in the U.S.A.Lantac USA manufactures the highest quality accessories for AR-15/M16 pattern rifles. Precision made in the U.S.A., rifles, muzzle brakes and more.