When we were very young and always trying stupid things, we woud drill the noseof 58cal Minie bullets just deep enough to contain a small amt of BP.
Then a .22rf primed case, bullet pulled from a live round (usually a 22Short when we could get them) was pushed into the hole base up so it was a tight fit .
CAREFULLY loaded with a hollow nose ramrod. The bullet would explode with quite a cloud of smoke and a bang if it hit a suitably hard object/surface.
Usually a plywood target backer would suffice and sometimes dense enough backstop dirt would do it.
Recovered bullets would have the nose shredded open as expected. They were already weakened by the drilling process.
Kids,,always have to blow things up...