When in HS, a friend of mine and I took apart several 100 Black Cat firecrackers and packed the power into a shotgun shell. We waited until about 10 PM one night and went to a local park that had a small amphitheater structure and set it off on the stage. Sounded like a howitzer !! The flash was so bright we could see our shadows (as we were running away) on the ground... one helluva bright light!! ... and booming sound !

Lesson - it's not rocket science to make an explosive device ! wink

McVeys was fairly crude, but one helluva explosion. NH4NO3 is a helluva explosive, just ask the folks in West, TX. frown
David (OFI)