"Custom Load" is not necessarily made with a large musket ball folks. :wink: To get accuracy capable of placing a musket ball into a man sized target, anywhere on the target at 100 yards or less (let us agree that taking a hit from a lead ball of nearly an ounce anywhere on your body probably takes you out of the battle) merely requires rolling a cartridge that is uniformly snug to the bore of the musket, yet loadable without damage to the paper tube..., plus consistant powder loads. This may require several more layers of paper than a standard musket cartridge needed. In effect you are making a paper "sabot" for the ball to remain in the same position each time it is fired, thus allowing you to learn the proper aim because the musket has become consistant with where it launches the ball.
There are references to men in marksman companies, making the cartridges. Each musket was probably made its own loads by its user, so no actual "set" combination of powder, ball, and paper, existed. So we need to experiment with our own loads to determine what works..., probably just as they did.
The problem though is after several rounds, the bore is so fouled, you can't get these loads down the bore, so..., either you swab the bore, or you switch to the overall smaller, standard cartridges, and as the battle progresses, you may even end up loading bare ball without any paper around the ball at all.
LD