If I am not mistaken, Pyrodex measure the same as black volume wise. If that is the case, when loading muzzleloading shotguns, square loads are considered to be optimum. To me, a "square load" means same volume of black as shot. Some say it is not a "true" square load Ness the wad column is also the same. Be that as it may, when loading a muzzle loading shotgun OR black powder cartridges, I weight the shot charge that I intend to use, weigh it on the scale, pour that into my adjustable powder measure (adjusted to the max), then push the plunger up until the shot is at the top, this gives me the VOLUME of the shot charge, then whatever that is, that is the setting for my powder charge. I then set whatever loading equipment I am using to show those amounts whether I am loading a ML or loading cartridges. IF pyrodex is used in equal volumes as black, this should work well with that as well. If it measures different than black, I have no clue. Have never played with black substitutes.
