Originally Posted By: MO1
What is an HBN coating, and why is it of benefit?


Hexagonal Boron nitride (HBN) is a binary refractory compound that possesses good lubricity and good chemical inertness. It is used in many industrial applications as well as some face powders and other cosmetics. Here we are using it as a way to mitigate copper fouling in high volume shooting conditions. Its application and purpose are very similar to molly coating bullets. I tend to like HBN better than molly simply because it is more chemically inert and cannot generate corrosive sulfides in the barrel under some storage conditions. Like all other bullet coating, it is not safe to assume that pressure will be reduced in a given load when changing from “naked” bullets to coated bullets; especially if you have a high quality smooth barrel to start with. Start low and work up.
John