I built myself a so called ''drop tube', a 3ft long tube made of brass that is supposed to ''settle'' the pieces of black powder so I can fit more of it into a case.
I did some extensive testing with two empty .454 casull cases and swiss 3FG powder, the difference between powder simply poured into the case and using the drop tube was a hardly measurable 2-3 grain. Not a lot.
Then I poured as much BP as possible into the case and gently grinded the bottom of it against a rough surface - this way I could get 2 x ~5 more grains of BP into the case,a total of 10 grains. So shaking / vibrating the case to settle the black powder is more than 3 times as effective as a drop tube.
