During the muzzleloading period the normal charge would be equal volume of shot and powder measured by volume not weight. However in order to increase the density of the pattern which would decrease the spread they would decrease the volume of the powder charge in relation to the volume of the shot charge. To reverse and increase the spread or decrease the density of the pattern they would increase the volume of the powder charge in relation to the volume of the shot charge. I have tried this with results that are somewhat in line with this procedure, in other words, pattern percentages did change but nothing that I would describe as noticeable.
All the best
