Some of my childhood summers were spent in the back room of a jewelery store casting wax models of custom rings/bands.

One summer the owner had me casting wax slugs for his handgun in the same fashion, which he used for DIY shell recycling.

Judging from the cardboard box they had setup back there for target practice, the wax slugs were very effective. As an adult I've wondered on multiple occasions if those wax slugs were actually a good alternative to lead for indoor self-defense where the risk of unintentionally shooting people through walls is high.