The conversion I have is an R&D drop-in, 5 shot. It requires the barrel to be removed to load and unload, but the 1860 I put it on can be disassembled without a mallet, just thumb pressure on the wedge.
I shot a Cowboy match with it last month and it was fine. Paired it with a Remington, and shot both with 45 Schofield with black powder loads. I was one shot short of a clean match.
They do quite well and are safe with smokeless loads, I wanted to make more noise and smoke that day.
The 5 shot R&D is SASS legal because it has cylinder lock notches between the chambers so the hammer can be set between the cartridges, making it safe.