You can always just roll your own cartridges or cheat and use Pyrodex pellets........... My Ruger Old Army .45 will handle anything I can feed it.
It takes a little time to get the hang of rolling them, but it was fun. I started out by rolling the paper around an empty .44 special cartridge with the .45 ball sitting on top so the paper was half way up the ball, then glued it in place. After they are dry remove the brass case and add the charge, then fold it over. It wasn't an original idea. I stole it from articles on the net.
http://www.hackman-adams.com/guns/aboutpaper.htmHistory of Paper Cartridges
Cartridges made of paper were the mainstay rifle and pistol ammunition of the American Civil War for both sides. The paper used to make paper cartridges was not waterproof. And the available gunpowder wouldn't work when wet.
Over 90% of the Civil War guns were loaded from the front end. Revolvers were loaded from the front end of the cylinder. Muskets were loaded from the front end of the barrel, the muzzle.
Paper cartridges are fat like a cigar (but shorter) and light colored like a cigarette. The ends could be tied with string or folded over and glued. Paper or linen cartridges are reported to have been used as early as the 1550s.
The soldier could rip off the back end of the paper cartridge and then pour the powder down the barrel followed by the bullet. They were taught to tear off the back end of the cartridge with their teeth. This worked until the teeth became loose. As part of the military medical examine, the doctors checked certain molar teeth matched for biting and tearing paper cartridges.
Metallic cartridges for new models of breech loading guns replaced paper cartridges in common military service as early as 1866. But the teeth requirement for military induction physical exams wasn't dropped until 1940. What else were they expected to bite so hard, uncooked food such as raw beef?
Ripping off the back of the paper cartridges took time. In the heat of battle, instinct is to ram and fire fast. That is, ram the new powder charge and bullet down the barrel as fast as possible. To do that, the entire paper cartridge was rammed down the barrel either opened or unopened. For this purpose, the paper had been soaked in potassium nitrate to make it completely combustible. Both the powder and the paper used in Civil War ammunition was highly combustible. Keep the cartridge box away from the campfire sparks!
Correctly loaded the powder end of the paper cartridge went down the barrel first. Incorrectly loaded with the bullet down first disabled the gun for the duration of the battle. The embarrassed soldier would throw down his musket and pick up the gun of a fallen buddy. After a musket changed hands several times, it was more likely than not to be unusable by being loaded incorrectly. One musket picked up from the Gettysburg battlefield had 22 charges rammed down the barrel!