When I was a kid, I remember taking a roll of the old style, flattening it out, then laying the whole roll on the sidewalk and pounding on it with a hammer. Kablooey!
ME TOO!!! Nothing like gunpowder for kids!
That pic has the caps we used in “Wasp” cap guns...those were serious loud but expensive to shoot. Those were the Cadillac of cap guns. I’m very surprised they still make them.