The coating on the bullets is called molybdenum, or "moly" for short. It is supposed to provide some lubrication to bullets and provide better velocity from a given powder charge. IMO, the mess it makes in your barrel is a greater negative than any small increase in velocity you might get. The way I see it, this is just another fad in bullets that will go by the wayside rather quickly (the Fed Premium TB Bearclaws were discontinued, eh?). However, there are others that really like the moly-coated bullets. It's all a matter of preference, I suppose.
