I've owned an assortment of BP handguns over the eons. I currently have a Ruger Old Army riding it's box for the last 20 years, had one before that - back when the 200th Anniversary issue was current - cost me a whopping $167 which seems cheap, but that was just a few dollars less than a contemporary Super Blackhawk!
I don't understand the obsession with paying a small fortune for an Old Army, then shelling out what it would cost to buy a decent 9mm or J-frame for a cartridge cylinder all for a "range toy," which is what they always end up being. Cylinders for the Old Army aren't true conversion cylinders in that they can't be loaded while mounted in the gun and must be removed, the back removed, empties pushed out, newbies dropped in, reassembled, and re-installed. That ain't exactly a faster process to reload an Old Army or any C&B revolver! The Old Army is just to gigantic for anything less than holster carry, and then, a Super Blackhawk (if one is being comparative) is the better choice for sheer power.
One of my most favoritest BP guns was an Uberti 1860 Army that I cut down to a 6" barrel, and actually carried, loaded with 180gr. Buffalo bullets! That thing would rupture a water-filled pain can at normal SD distances, and while not as potent as an Old Army CAN BE, it was potent enough in a much more compact, carriable format, plus it pointed like a finger making it very fast to put the first round on target when drawing from concealment.
But almost lost to the modern world is the fact that NOBODY was using a powder flask, loose ball, and grease pot to reload C&B revolvers during their heyday.
Back to reloading. A major reason the '58 (really '63 New Army) Remington was so favored by yankee troops - aside from being $8 cheaper per gun than the 1860, was its complete frame - copied by Ruger, and method to quickly drop out the cylinder - also copied by Ruger, but not as well done as the original which was purposely designed for the base pin th slide forward and be retained while the cylinder was swapped out, whereas the Ruger requires a tool to lock and unlock, and the base pin will draw completely free - NOT a good idea on a gun meant for rapid recharging in combat. One can reload an New Army faster than any modern cartridge single-action using spare cylinders, and even at today's inflated prices, they're much, MUCH cheaper than so-called conversion cylinders!
But, since the entire Colt line was not so easy to cylinder swap, it, and the New Army, were generally fed a diet of factory fresh cartridges, generally 6 to a box with 6 percussion caps included. Even with that, reloading time for a percussion revolver rivals the single-action cartridge models because there's no need to kick out empties one-by-one, just insert a cartridge, ram, proceed, then cap - pretty fast by the standards of the day. This is a way to bring out that Ruger Old Army and start enjoying shooting it (again?)