Original revolver, or a repro? If it's a repro then factory ammo is fine. The factory loads are kept to a lower pressure in case they get stuffed in an original.
If it's an original, then as an open top it is likely a conversion whether factory or otherwise, then go to Blackpowder & Antiques there is a sticky there you should read through about shooting smokeless loads in antiques....OR load it up with Goex, maybe use some filler to reduce it even more (because it's an open top, just in case - watch the cases for signs of stress). Start very light if this is an original.
I strongly suggest you don't fire factory rounds through an original...at least not until you've carefully evaluated it/had your gunsmith check it using reduced loads...just my 0.02
Pressures are available on any of the load data websites (IMR for example). Watch the units though if you are comparing load pressures (CUP vs PSI) as the two are not the same.