Seadog28: I offer some advice. On a patched round ball the patch, and not the ball, contacts the bore. You therefore should not have any lead fouling. On a conical the argument is that fouling only occurs at the higher velocities but when ever I shoot conicals I get bluish streaks in the cleaning jags that indicates lead fouling. In any event, start out with patched round balls. A thicker patch may be harder to seat but often yields better accuracy.
On the powder, the substitutes are just as corrosive as black powder. Black powder ignites better and ought to be used whenever possible.
A very few hunters put a lubed wad over the powder and then put in the patched round ball. This is usually unnecessary but in a few cases the accuracy might improve. Generally you put the PRB over the powder and seat it firmly on the powder.
Regular caps are okay. Caps and nipples vary and you need a good fit. In some instances the cap may seem firmly on the nipple but might be a little too small. The first drop of the hammer just pushes the cap firmly against the nipple and the next hammer drop fires the gun.
If you swab between shots- or whenever you swab, the cleaning jag may push residue in the bore downward and plug up the hole from the nipple. SO... whenever you swab point the muzzle at some grass or sand and fire a cap to clear the flash hole. If the flash hole is cleared the blast of the cap will move the grass or sand a bit.- Then reload.
If you ever get a misfire lay the gun on a bench- the muzzle pointed down range and wait 2 or 3 minutes. If you have a CO2 dispenser you can blow out the charge and ball. If you don't you can often remove the nipple- put a few grains of powder into the drum, replace the nipple and try again- this will often fire the gun although it may have a slight delay or hangfire- hold the gun on target a while to be sure.
If the accuracy of the round ball isn't that great- try reducing the powder charge- that sometimes helps.