A little dampness in the drum can be a big pain in the butt. When those kinds of misfires occur, I usually just take the side screw out of the drum, or screw off the nipple, and put a pinch of black powder in the drum and put the screw or muzzle back in. That's enough to power through whatever little damp powder there is that a No. 11 cap doesn't have the power to get through.

[Linked Image from i.imgur.com]
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