It seems like I should have posted that question with a picture of the device. Well, I beseech you -- behold my MS Paint skills!
Okay, some of you are more visual than others. Still seem like it might work? Do the numbers make sense? Am I off my rocker? You decide!
To review, the device falls from a great height or gets lobbed from behind a sturdy wall. The impact crushes the brass terminator, driving the firing pin (more like a hammer, innit?) into the percussion cap. Cap ignites the powder, bursts the segmented iron egg. Pieces of iron fly all over with fire and great justice.
Here's a question that google has failed me on: why do falling bombs make that whistling noise? Is it a function of their shape and mass?