Hawg Haggen said:50-90 or 50-100 Sharps will work.
Rifleman1776 said:I don't understand wanting to mix an old traditional style with modern stuff.
Just go to the hardware store and buy some copper tubing. Squish one end in the vice, drill a hole for a string in the squished part, add powder amount you want, note how far up the tube it comes and cut.
With a little use it will get appropriately grungy and look old and will serve you for many years.
Here is a list of cases of every kind & the amount of water they will hold. Water is very, very close to Black powder in volume & density so it's a pretty good indication of capacity by volume for B/P.