Wikipedia says, "The Lubalox coating was to protect the barrel rifling", but there's much more to it than that. The Lubalox coating was supposed to give it less barrel fouling and more shots possible before cleaning is neccesary. But it was also supposed to have less friction, less chamber pressure, higher velocity, higher energy, and probably something else that I'm forgetting. BTW, it's a thin layer of black oxide and not moly or teflon.