Hey, you guys really missed out on the fun if you just used paper rolls of caps. I remember having a revolver-type cap gun, it used little plastic caps, they were really REALLY loud. The caps were little short cylinders with one open end and the blasting charge in the other end, they are quite similar to the firing caps used in ancient rifles. ISTR reading they were banned due to potential hearing damage to young kids. They were just as loud (if not louder) than a real gun.
And for you maniacs that liked blasting a whole roll of caps at once, I’ll tell you my favorite safe-and-sane fireworks abuse from my childhood. Take a little box of those snakes, you know, the little black pellets you light and they make a huge stink of smoke and extrude out a “snake” of burnt carbon… anyway, take a box, or two or three, put them in the corner of a paper envelope, then crush the whole packet with a hammer. Crush it until it’s a powder, not many chunks left. Then pour it down into the end of the envelope, twist it into a little packet, and light. It makes a HUGE snake, in one huge burst of pyrotechnic frenzy. Much more fun than those single pellets, and not dangerous (well, not any more dangerous than lighting snakes generally).