I recently bought a Pedersoli SXS muzzle loading shotgun kit and finished it (it was already fitted, but needed the stock and metal finished). The locks, hammers, and nipples all worked as advertised; so I fired a few caps on the nipples and proceeded to load. The right barrel fired first time with a slight delay, but the left barrel failed to fire several times with several brands of #11 caps. I then pulled the overshot card, dumped the shot, pulled the wads, and dumped the powder. I then took the nipple off, cleaned it, fired some more caps (to make sure it was cleared), and reloaded (powder charge, 2 waxed wads, shot, overshot card). It fired after 2 tries, but was almost a "hang-fire". I loaded it up again the same way, and it would not fire. I then, fired the right barrel and swapped nipples with the left (making sure the nipples were clear) - still, no ignition. After many more tries to fire the left barrel, I finally pulled the load and cleaned the bores before putting it up. I was using Pyrodex RS for my powder, which works in all my other black powder rifles and shotguns. Any helpful suggestions will be appreciated? I can get my hands on some black powder, if it works better in this type of gun, but it's not readily available in our area. Thanks