Finding wax.

When I worked in a cardboard (corrugated) box plant, we used huge amounts of wax to coat cardboard that was used for seafood and chicken. It came in stacks of 10 pound (I think) slabs.

There was always a huge pile of discarded wax. If you're near a plant, might get some discarded for free. If it gets dirt or oil on a block you can't use it on paper. But you could scrape that off easily.

It comes in various grades. Curtain coat was a shiny white and brittle, then there was a yellowish one that was tougher.

I tried using some of it as bullets, standing an empty cartridge in a pan of liquid wax then letting it harden to fill the neck with a projectile. then use a primer for propellant. The books says it works but it didn't for me. The wax didn't hold together, it just shattered.