I'm in the process of building a .62 pistol. I've port fired huge charges from it without any ill effects on the barrel. My current setup is with model airplane glow plugs, they work fairly well but only for so many shots. After that, the plug either becomes too fouled or it burns out. I'm curious as to what else could be used to ignite the charge without priming (that means no flint or caps). Would something like a spark plug work? Please don't make this a safety lecture, I'm well aware of the dangers of black powder.