"It will ignite without a CAP!"

Been doing Explosive Ordnance Disposal work since 1959. Yes, black powder is dangerous and is susceptibleto initiation bystray electrical current.Just how susceptible, no one knows. In the early 1980s i worked on a job overseas where a 1870s-80s black powder magazine was struck by lightning and blew up. Rocks as big as cars were thrown for nearly one-quarter mile. We cleaned out some more magazines that contained all kinds of 1880s stuff, including black powder.Would you believe that there was even pelletized black powder with a hole up the middle, just like Pyrodex pellets.

i do not know how suscptible Pyrodex and the other "substitutes" are to stray electrical current.

These guys could not get loose black powder to ignite, apparently the graphite coating just conducts the current all over the place:

http://www.ctmuzzleloaders.com/ctml_experiments/sparks/sparks.html