The only thing I do to try to keem my dumps close it ti fill the tube at least 30% full.......
then tape it a few times to settle the powder and toss three drops back into the top and then...........test for the grains that I want for the load.

Even max 9mm loads of today have a safety area so you should be good with a weapon in good shape.
Nato is pushing the limit and +P loads depend on the weapon.