First, do some internet research on cleaning blackpowder. Substitute B/P might require different methods, but I do not know shoot only real B/P.
If you live in a damp climate then you may want to clean your "hogleg" shot with real blackpowder after shooting or within a day. In my dry climate of central New Mexico I let them lie for four days or more and there is in corrosion.
Properly cleaning and caring for black powder fireams NEVER caused corrosion problems. The worst thing is improperly using the tools to clean the weapon and leaving wear and tear marks on the firearm.
The newer folded head .45 Colt cases cause no pressure problems over the older ballon head cases. Blackpowder in a cartridge case is almost never going to cause pressure problems.
Never load any blackpowder firearm, be it a real muzzle-loader with ball and patch or cartridge with an airspace between the powder and projectile. The airspace causes a bulged barrel (I'm not sure how).
Magnum primers are good to create a positive ignition. And a heavy crimp.
Also it is a good idea to use a card-wad or fiber wad (MidwayUSA has them) between bullet and powder to avoid leading in the cartridge loads.
Soft lead bullets are better than hard-cast because they "bump up" and fill seal the bore better. Also, as mentioned above, use of a specific black powder lube, like SPG, is highly recommended.
There are online purveyors of black-powder, SPG lubed bullets for cartridge loading. Go to "Buffalo Arms Company", "Goex" (on MidwayUSA as well), and others.
Blackpowder cartridge loads can be as accurate as any smokeless powder load. In the .45 Long Colt, a full charge of 3F behind a 250 grain bullet, in a modern case, (about 35 to 37 grains) is capable of producing 900 FPS. A potent load.
Getting a stainless Ruger Vaquero in .38-40, .44-40, .44 Special, .44 Magnum, and .45 Long Colt would be the way to go. If you want a Vaquero in .38/.357 buy one and shoot B/P in it. You will probably get decent .38 Special velocities but not .357 Magnum velocities. Then...if you tire of B/P you have a stout revovler for stout .38/.357 loads.
I liberally rinse and scrub ever nook and cranny of of B/P revolvers (cap-n-balls and conversions) with Windex with VINEGAR (not ammonia)...mix the Windex half-n-half with water. Then I wipe off what I can, shake and blow off the rest; then liberally spray the entire weapon's crooks and crannys with WD-40 or Break Free. I let the oil soaked weapon sit for a few days and then wipe out/away the excess and store them away.
P.S. pull of the wood grips before doing this.
P.S./P.S. If you're married do your cleaning outdoors or somewhere outside the house, the "War Department" tires very quickly of the mess and smell. Contrary to misconstrued opinions B/P, B/P cleaners, even Hoppe's #9 is not an aphrodiesiac to most sane women..............
since it was black powder originally, the SECOND thing that came to my mind was something about balloon head cases and the interior dimensions being different on BP versus smokeless powder. 
