When you refer to the pellet being "jammed" in the barrel, I'm not sure of the situation. I guess the closest thing I've had is having 2 pellets accidentally loaded, but they always shot out without a problem. I once had an oversized cleaning patch stuck in a barrel, and it was very tight. I removed the barrel and silencer and tapped it out from the breech using a cleaning rod. I can't argue with using a wooden dowel, but I don't think it's necessary, if you are careful with a rod, and can use it from the breech. Depending on the barrel configuration, whether an air stripper or silencer is involved, you might be able to work from the muzzle, being careful of the crown (should not be an issue with a wood dowel).