Re: What is black hill ammo loade with?
Based on my experience it is most likely a canister grade powder supplied by St. Marks powder company. If it is, you will not be able to purchase it.
I wouldn't worry what powder it is. Just try Varget, H-335, Win-748, AA 2230 or one of the Western brand powders that are suitable with your chosen bullet weight. You should be able to duplicate the velocity and accuracy of your favorite load without too much effort.