You have three options: 1) Remove the nipple, pour a little bit of fine (ffffg) powder into the ignition passage, replace the nipple, cap and fire. 2) There are CO2 devices that will expel the ball and powder. The ball must be all the way down on the powder or against the breech plug. As always, make sure the firearm is pointed in a safe direction. The ball will be expelled with some force. This is the safest procedure for removing a stuck ball. 3) Use a ball puller on a ramrod and pull the ball out the barrel.
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