When I shot flintlocks in the '70's, I used balls cast from a scissors mold w/o a sprue plate. They required the sprue to be removed with a pair of diagonal pliers. I shot these balls with denim spit patches that were cut at the muzzle. I used a homemade ball starter to place the tightly fitting ball/patch combo flush into the muzzle for trimming with the patch knife, and then an additional 6" down the bore with the long arm of the starter.
I just trimmed the sprue as closely as possible with the dikes after casting, and that was it. The sprue was centered face up when the ball was placed on the patch material, and that was that.
It has been my experience, and the experience of thousands of other patched ball shooters; that round ball barrels with rifling designed for patched balls, and NOT bullets, ARE INCREDIBLY FORGIVING OF POWDER CHARGES, BALL DIAMETERS, PATCH THICKNESSES, AND LUBES.
That being said, there will always be a combination that will give stellar accuracy at a given distance.
Remembering, that a ball can be ballisticly accurate out to 100 yards with sub-M.O.A. accuracy, even in the small calibers like .32.
ON TARGETS, NOT NECESSARILY ON ANIMALS.
Talk with the men that have hunted for decades with patched balls, and the same info constantly keeps coming up.
Try to get as close as possible. Do not treat the patched ball rifle like a modern inline m-l rifle, or cartridge rifle. IT SIMPLY DOES NOT HAVE THOSE TYPE OF BALLISTICS. Rainbow-like is how they are often described.
On the other hand, A PATHCED BALL HAS A DISPROPORTIONATE ABILITY TO KILL THAT THE BALLISTICS TABLES SIMPLY DO NOT ILLUSTRATE.
Edit to the above:
Learn YOUR RIFLE, what load it needs for best accuracy (usually NOT the heaviest load). This generally take a bit of experimenting, and time.
.45-.50 caliber is usually sufficient for deer if you will shoot within 75 yards, and NOT TAKE MARGINAL SHOTS.
.54-.58 caliber is generally recommended for elk, as most hunters agree they are harder to kill.
As the ball increases in diameter, it carries more kinetic energy with it to a farther range. Always remembering that a ball sucks ballisticly, with its rainbow trajectory.
Most experienced hunters with the patched ball do not consider anything under .62 caliber suitable for shooting past 100 yards. And that is with slow twist barrels that pretty much DEMAND larger than 100 grain POWDER CHARGES to obtain optimum accuracy.
In order to have reasonably flat trajectory up to, and past, 100 yards with a patched ball; AND HAVE THE ENERGY TO HUMANELY KILL a large animal like an elk with a quartering shot; requires a big ball with a large powder charge under it.
Big balls with big powder CHARGES require HEAVY RIFLES TO TAME THE RECOIL that the large powder charge generates. Unless you are a masochist. They are generally a young man's game.
I am 66 years old, and I KNOW THAT I AM PAST MY TIME when I WANT to pull the trigger on a .62-.66 caliber English Sporting Rifle, weighing 14-16 lbs, and NEEDING a 150-175 grain charge of Swiss ffg black powder for top accuracy. Even at 40 years old, I don't think that I would have wanted to tote such a rifle around for very long.
That's the Law of Diminishing Returns with patched balls. As all of the African hunters found out to their detriment.
BIG BALLS = BIG POWDER CHARGES = BIG RECOIL = FLATTER TRAJECTORY = HEAVIER RIFLES TO TAME THE RECOIL