When I load my pre loads for any of my ML rifles or C&B revolvers I will back it up with a scale mostly to get as consistent loads that I can.
My rifle measure "with swinging funnel" to the scale is the most consistent, I simply pour the powder into the measure till it over flows a bit then swing the funnel cutting the charge to the right level.
With my C&B revolver loads I can conistently keep a 34 grain "for hot loads" & 29 grain "for normal target" charge every time "as measured by the scale."
For my Zouave I can keep 59 grain pre loads at the ready using my method...

Tapping has allways made the most inconsistent loads for me, maybe I'm not that good at it but I've yet to get the same load twice by tapping.