The proprietor of HAT bullets used to be a sponsor here, but I don't think so anymore. There were some heated controversies concerning his bullets and BC claims, etc.
Not sure where he is or if he is still making his bullets?
Here's a thread to check out and if you go to the bottom of the page of the linked page you'll see more HAT thread links.
I have some of the 30 cal's. If you are interested send me a PM. My gun room is going though a remodel and the bullets are packed away, not sure if they are 180's or 190's. HAT says the BC is .711.