Hi, I like the steam hammer, and I do remember the smell of caps when exploded. Apart from the toy cowboy guns that would take a reel of caps and advance them automatically, we used to get those rocket shaped cap bombs, and you could get singular disc caps to use in them. They could be used to make others jump, by throwing the bombs down just behind them when they wouldn't expect a loud bang. We later discovered that you could achieve the same effect by trapping a cap between two bolts, screwed lightly together into a nut, but you had to make sure they hit onto one of the bolt heads when you threw it down.
Regards Nick.