Same as modern smokeless loads. When you buy shot shells they often have "Dram-equivilant" marking. That refers to the velocity that particular shell would have when loaded with the number of drams (27.5 grains) of real black powder that would result in the same velocity. Real black powder gives up nothing in velocity or range to smokless powder loaded shot shells. Well, there is the smoke, but if you pick a windy day even that is not a problem.