I remember something similiar that appeared in a movie, probably in the 1950s. It was a Western.
Someone was being held captive in a barn. He happened to have a cartridge with him, conveniently enough. It may have figured in the plot somehow early, like it may have been a souvenir of something or other. The hero at one point puts the cartridge in a hold in the barn door and sets it off with a rock and a nail and naturally, manages to hit the bad guy. Good idea but about as likely to work as making an explosive out of cow's milk. Aside from the fact that it would explode rather than "shoot," it would take a lot of luck to hit something like that, at least the first time you tried it.
Don't try that at home.
Shoot low, sheriff. They're riding Shetlands!
Underneath the starry flag, civilize 'em with a Krag,
and return us to our own beloved homes!
Buy War Bonds.