Trust me, I know what you mean. Its honestly very nice and I am trying to reduce my inventory of unused guns. So I could use my ROA as black powder and now with the 45 ACP cylinder it takes the place of two guns. It would just be nice to have a spare BP cylinder.Over the years I do not recall ever seeing a ROA cylinder made by the manufacture for sale. Perhaps they were available when still being made. Best you may be able to do is purchase a ROA that is broken and salvage the cylinder from that. Only problem is they don't often break and when they do, they get repaired.
I can't imagine how you would break a ROA?
I suppose loading a cylinder with Bullseye such that you can barel squeeze a .457 ball down it would do it.
I have every intention of purchasing a cylinder from or made by Classic Ballistix.