Powder Measure
Also: Powder Thrower
A device that meters a powder charge by volume using a rotating cavity, then usually trickled up to an exact weight for precision loads.
A powder measure throws a charge by volume rather than by weight, using an adjustable cavity in a rotating drum that fills with powder and then dumps it into a waiting case. Turning the metering screw changes the cavity size and therefore the approximate weight thrown, which is fast and convenient for loading in bulk. The volume method is repeatable enough for general shooting but carries a small charge-to-charge variation because powders settle and pack differently each throw.
For precision work, handloaders throw a charge slightly light, then bring it up to the target weight in grains with a powder trickler while watching a reloading scale. How cleanly a measure throws depends partly on the powder shape, since fine spherical grains meter more smoothly than long extruded rods. The measure handles the bulk of the work and the scale provides the final accuracy.