Hi Ted, I have two .45LC conversion cylinders (one Howell, one Taylor) for my 1860s, they work great. Get the barrel wedge correctly set up and one can change out a cylinder on the 1860 faster than an 1858 Remington. If you modify a BP revolver with a loading cutout to assist loading cartridges, it then becomes a regulated FFL firearm. My choice was to not add a loading gate type conversion cylinder so as to keep the revolver unregulated. For the 1860, I prefer the Howell over the Taylor conversion cylinder.
Regards,
Richard