To the best of my finding and buying this powder, they grade it just the same way as rifle powder. they use a mesh size to grade it. The first batch was listed as blasting powder, then the next was cannon powder, cannon powder is not coated, where rifle is a coated powder. the first batch looked like pea gravel, but worked ok. the newer , fff cannon powder is a lot finer grains and faster burning, this is the powder we are now using.
Gerald