Yeah, I would go the shoot it out route. Pull the nipple. On the chance that everything is damp or oily in the breech, give it a good long blast with carbuerator cleaner through the nipple hole and drain that out. Let it sit for an hour or two in a verticle position with the muzzle down to make sure everything is dry at the breech (or blow it out with a compressor or "canned air"). Trickle some powder in there and give it a shot. It should come out.