For that type of powder measure there is no need for perzactness. If yer rifle wants 72.5 grains on the bench at the range, it's intended target in the field won't care if you are using 80 gr. or 65 gr. They can be made approximate. I have made several in what could be half or one third charges and the shooter counts wat he wants. e.g. one dump for squirrels, two dumps for deer, etc. If a measure is made that holds more than the shooter wants a wad of tissue or beeswax at the bottom can fix that.