I have a Citori Special Sporting Clays with about 10,000 rounds threw it. It started misfiring on the bottom barrel. I removed the firing pin, inspected it, and cleaned it. Next I switched the main springs around, to no avail. Finally I shimmed the main spring for the bottom barrel. This helped some. I called our local gunsmith to order new main springs but he did not feel that this was the problem. Any ideas for this annoying problem before I ship the gun off?