The entire carrier assembly is QPQ (Quench Polish Quench) Nitride coated Black this is a specialized type of Nitrocarbrising Case Hardening that creates a very hard smooth surface with increased corrosion resistance and low coefficient of friction. The carriers patented and patent pending design features unique shrouded and forward facing gas ports that have also been resized so that gas is vented differently to a standard carrier. This results in a system that runs flatter with a smoother energy pulse with a softer start to carrier movement. In addition the system also runs cooler and cleaner there is also less pressurization of the upper receiver when running a suppressed barrel. The flared boss at the tail of the carrier enhances the BCG’s position within the buffer tube at the time of cycling and makes it more consistent resulting in smoother operation. All critical dimensions are hard turned / ground after heat treat and the gas key has been hard chrome lined for the best possible wear resistance