The measures are supposed to be set/calibrated/made to throw " equivalent black powder" volume. This means if you are setting your measure at the 90 grain mark, with true black you would get 90 grains (maybe ). And with Pyrodex of the same grading you would get 90 grains equivalent by VOLUME. The Pryodex would weigh less on scales.

So your measure isn' t telling you a weight, it' s telling you a volume. Some powders such as Triple7 would be much hotter in that same volumetric amount so you must reduce your volume setting about 15% or so to get essentially the same force from the powder' s ignition.

Clear as mud? Well that isn' t where it gets confusing. Where it really gets confusing is trying to relate this information to pellets. Pellet volume and weight are basically irrelevant to these common volumetric measures. Really, in the case of pellets, all that matters is the equivalency put on the packaging by the manufacturer. And the effect on your wallet.