How to make gunpowder with flint and matches

This video tutorial will show you how to correctly make gunpowder / flashpowder / Armstrong's Mix using just flint and matches. Go grab some flint, which is a type of stone that sparks when hit, and some matches and you're ready to build some awesome gunpowder. You're going to need a fine metal file to to grind up the flint stone. After completing these instructions, you'll have some great flash powder for use in your pyrotechnics.