To get back to the OP's original 'IF' I were to leave a cap and ball revolver loaded for any period of time, I'd go with an unlubed wad. Some of the wads you can buy commercially state they are lubed, but it is a dry lube. I always relube them with one of my concoctions as I feel they don't have sufficient lube on them. OR-punch out wads from dry felt and use them unlubed, but that may run the risk of a small rust ring in the cylinder, can't say. What may be the best bet is to load powder and seat a tight lead ball over the powder, no risk of any lubed wad of any kind contaminating the powder. As long as the revolver is stored in a dry, preferably cool area there should be no danger of powder contamination. Question to the OP, would you plan on leaving it capped for quick use, maybe none on the nipple the hammer is resting on or leave it entirely uncapped. Ifin you had intentions of leaving it loaded for defensive purposes or fast critter control, not having it capped would IMO make it equal to throwing a rock as you may not have the opportunity/time to cap. BUT----As I stated in my previous post #7 there are better firearms available for any personal defensive or critter control. Ifin 'thee Ol rubber is meeting the road', any of my cap and balls 'if they were loaded', would be the last firearm I'd use, even any of my Dragoons or Walker (unless of course I'm out shooting and all I had were some of my cappers). If you just want a loaded percussion revolver all loaded up for the next time ya go shooting, loading before that adventure takes little time. JMO's. CC