Metering Quality of Different Types of Powders

Metering refers to the ability of the powder to fill a volume (the disk cavity) repeatedly with a minimum number of random voids. This results in more uniform weight powder charges. Some powder grains, because of their shape and size, have the ability to automatically arrange themselves in an orderly and repeatable pattern with few gaps or spaces between the individual powder grains. These types of powder meter better. Spherical (ball) powders do this best. Small grain extruded flake powders are almost as good. Followed by extruded powders cut to uniform short lengths. Large grain flake and extruded stick type powders where the individual sticks vary in length meter least well.

If the Disk powder measures are used on a Turret Press with the auto index function installed, the metering quality of any powder will be improved. The start stop action of the indexing agitates the powder and settles it in the meter chamber resulting in a more uniform charge weight.