My neighbor just called to inform me that he bought a .50 black powder. This is not an in-line gun. Without doing the proper research he poured some powder in, forced a bullet in and tried to shoot it. Only the blasting cap ingnited. He wasn't sure if the powder went off or not, so he poured more powder in and forced another bullet in then realized that he had two loads in the barrel. I have no experience with these guns (and he has even less) and I know that it is dangerous to try and fire the weapon as is. So any advice on how to empty the barrel safely? There is a plug of some sort at the back of the barrel that I assume is screwed in. My neighbor has tried removing it with a plyers (don't ask me why) but couldn't get it to budge. Is it safe to put the barrel in a vice and try to back this plug out with a wrench? I want to help him out and keep the situation safe. Please let me know if you have the answers. Thanks.