For those who wonder if standard caps have enough fire in them for good
results, here is a picture I just now took of a standard CCI no. 11 cap. You
can imiagine what it looks like in the chamber itself.
Somewhere I saw a video of a guy with a blackpowder derringer - he was putting caps on the nipple (no powder or ball) and vaporizing mosquitos when they landed on his arm.