Gun powder is flamable but like tabby said it don' t just burst into flames all by itself. I can think of many things that are in my apartment that are flmable. Charcoal lighter fluid, gasoline, liquor, wifes hair spray, preloaded bullets and shotgun shells, lighters, matches, etc...etc...

Just try to explain to them that it is as safe as many of the house hold things that are in the house now. That you will store all of it properly (garage is not reccomended due to no climate control) and use all safety precautions.

Man, more parents should be like me. Just kidding.