What you are talking about is often referred to as a "gallery load" . . . RBs were often used not only in pistol cartridge loading but for rifles as well. Like any other BP straight wall cartridge, just make sure your load is compressed when you seat the ball. A felt wad, a cardboard wad, etc. can easily be used over the powder but remember that whether powder and ball or cartridge with powder and ball, you need some BP lube of some type to keep your fouling soft.
In my Uberti Cattleman - the chambers and throats are "generous" and it shoots well with either a .452 or a .454 projectile -BP or smokeless. If you shoot your cartridges in just one gun/conversion cylinder - you can get by with just end sizing the end of the casing instead of full length sizing. Once sized, a 454 RB should be a nice tight fit but you still may have issues with "ball jump" in the unfired cartridges if for some reason the "fit" isn't tight enough. you can always seat the center line of the ball below the case mouth just a tad and then either put a slight roll crimp or a slight taper crimp on it.
Those Schofields look great Bishop Creek! While I mainly load the LC, I have a couple hundred of the Schofield casings as well just to have fun with the historical cartridge.
I have sold my .357 Handi-Rifle but I used to load up RB BP cartridges for it and it shot well with them out to 50 yards. They weren't as accurate as a conical but still a lot of fun and able to keep them on the paper with not problem. I have even loaded 8 X 57 Mauser (smokeless loads) and shot them out of my 1907 GEW98 with RB Gallery loads and smaller charges of Red Dot, Unique or Bulls Eye and the same out of my 30-30s. Good rounds for pinking and killing cans.
