HI!
You are going to REALLY Enjoy your Ruger!
I have shot many different type of Blackpowder handguns and the Old Army is hands down the most reliable of the Cap n Ball Revolvers....
I DO enjoy shooting the other flavors as well (1860 Colt clone, 1858 Remington clone, 1873 Percussion Clone), but the Ruger is the least frustrating to shoot in many ways!
The Old Army is not usually plagued with cylinder binding from either a cap fragment or residue build-up etc.
I generally shoot a "Replica" Blackpowder such as American Pioneer Powder, and I want to try the replica powder from Hodgdon called 777. Goex, well known for their Real Blackpowder, also makes a Replica powder
Many people prefer the Real Blackpowder and that is fine as well... just more time spent cleaning up, and the process is much more odoriferous than when one cleans up after using one of the "Replica" powders.
I personally do not mind the smell of real Blackpowder, either shooting it or cleaning up after shooting, but my Wife sure appreciates the lack of smell when I use the replica powders.
I have not tried the "conversion" cylinders as of yet, but they DO look interesting.
All in All, Congrats on owning a Ruger Old Army!!
Ed