Query on an early Chrissy present

[Patrick Chadwick]

It is a BP powder dispenser.
One scale is in grams, but since the density of powder can vary, it is really a volumetric measurement, not a weight measurement, So the other scale is calibrated as a volumetric measure - most likely cubic centimeters. Many BP shooters prefer a volumetric measurement to ensure a consistent filling of the cartridge case.*
Take an old disposable plastic syringe (from your doctor, dentist or "Apotheker"). Cut the end off closely. You now have a plastic dispenser calibrated in cc.
Use the syringe to dispense 5 cc of BP or something like sugar or semolina into the powder dispenser and see how it matches up to the scale on the brass.
Let me know if I am right!

*With a bit of practice in consistent filling and dispensing one can easily achieve a +/- 0.2 grain tolerance in a powder charge. To do better with a weigher is extremely time consuming and not worth the bother with BP charges of 40 grains or more.