For the flintlocks in .69 cal., the service charge was 120-grains of very coarse Fg powder. Fully ten to fifteen grains of that was intended to prime the pan of the musket.
It was shortly discovered that simply changing from flint to percussion ignition improved muzzle velocity, and the charge was thus reduced to 110gr. to 100gr. I don't think that whether or not the cartridge was made single-ball or buck-and-ball made a whit of difference in the powder charge, but I'd defer to people far more conversant than I about the paper ammunition.
@RSMorris: Are you going to do some Minie/Burton ball cartridges too, or just the .69 smooth-bore?
At some point I should try to post some of my own efforts in making cartridges. I've tried to make French-style and also some British-style Brown Bess cartridges for the Texas Revolution, but those latter ones fell apart relatively quickly. The former are pasted/glued and crimped, while the British-style is just twisted closed, not carefully folded like the U.S. cartridges... Makes a real difference!
The three-piece paper cartridges of early Minie/Burton, British Pritchett-Enfield, and Norwegian kammerlader take a bit more practice, but they are super-nice cartridges. Most Minie/Burton cartridges I make are a bit slapdash, based on two identical sized pieces of paper.... I intend to make some templates out of an old plastic cutting board I no longer use, since the cardboard ones I made before are getting worn. I know that sheet metal templates are also available, such as those from Eras Gone and possibly some other similar sites.