How to Make Gunpowder: 8 Steps (with Pictures) wikiHow
1 Get your hands on some saltpeter. Saltpeter is the common name for potassium nitrate. In the days when black powder was widely used, saltpeter was manufactured from bat guano or made from horse urine and other "manure soils." [1] It's used in many fertilizers, as part of science projects, and in certain recipes.