There are two main causes of misfires. Common among new recruits is to let the barrel be lower than level which, especially if they lean forward, will spill the black powder down the barrel, possibly too far from the nipple hole to set off the charge.
The other, and most insidious, is not taking the nipple off the gun to clean it out thoroughly. On Springfields there is the little screw as well as the nipple to be removed. The caps leave a hard deposit in the passageway that just cleaning the barrel doesn't get at. I thought I was giving my weapon a good cleaning until one day, I actually dug into the nipple with a sharpened piece of coat-hanger wire and found there was quite a build-up of hard deposits that narrowed the hole in the nipple. Once I cleaned it out well, I determined to clean it thoroughly after every event. I don't have misfires any more as a result of learning to keep it clean, and keep it angled slightly up when firing.
Good idea. Also it never hurts to clean the nipple area and the clean out screw area with a pipe cleaner soaked with a black powder solvent between the battles as black powder does leave quite a buildup after firing. If you do get a misfire during a battle reenactment it helps to have a nipple pick with you and a quick clean out of the nipple hole will more than likely cure any problem.
