Boron Nitride coating?

Got my shipment of Deep Curl bullets in (180gr 30 cal, 150gr .270, 160gr 7mm and 140gr 6.5mm) to my surprise when I opened the 6.5mm it had a very dull finish on it, I looked on the box and it says it is Boron Nitride coated. Never heard of the stuff before I assumed it is some kind of lubracant but know nothing about it, and I am still confused why the 6.5mm is coated and all the others are not. Anyone familiar with this stuff?

The latest snake oil.

http://www.davidtubb.com/boron-nitride-coating-bullets

rc

I've been using it for about 3 or 4 yrs now. Works like magic. Keeps your barrel from heating up as much. Prevents coppering (somewhat). Much neater than moly and doesn't build up a hygroscopic crust. Reduces first shot fliers. Easy to apply. What's not to like.

Why would they use it on 6.5mm and not the others? Or are they doing that on all of them now and I just got old batches of the others, but Deep Curls have not been out that long.