I like the Pedersoli brass adjustable measure. My Great Grandad told me to load up a rifle until it shredded the patch, then back down the charge until the recovered patch was intact.
On a pistol, Great Grandad said, "The cylinder won't hold more black powder than the gun can handle, so just fill it and shoot..."
I shot my 1858 Remington that way for 20 years with BP and never had an issue with excellent accuracy.
Pietta recommends 22 grains BP maximum on my new '62 Police, so I was thinking 15 grains of Triple 7 FFFg would be a good place to start....Thoughts????