My dad recently gave me 3 black powder pistols none of which has ever been shot. One is a Ruger Old Army. The other two are single shot percussion pistols. I have shot bp a few times, so the process of loading, capping and firing...etc isn't too foreign. I do have a few questions though. The Ruger's manual says .457. Would I be okay using .454 diameter balls? What other diameter balls would work well? Also, the other two pistols have no markings indicating caliber. Should I just buy a set of calipers and measure the barrel to find out what caliber they are? Is there another way besides that to find out the caliber? Also, about how much powder should I use when firing them? And finally, although I have shot bp, I've never cleaned one. Are there any special considerations when cleaning bp as opposed to smokeless? Sorry for the long post, but any advice/tips/warnings...etc will be greatly appreciated.