Next, I read his "Like Fire and Powder," a discussion of the chemistry and characteristics of black powder, and how to make excellent powder safely, on your own.
On deck is his study of the Pritchett bullet "The English Cartridge," widely used by the Confederacy during the Civil War.

Brett has a fascinating Youtube channel, Paper Cartridges, and here is his presentation on the Pritchett bullet. Try it. You'll like it.
https://www.youtube.com/watch?v=0o8ag9EhY0w&t=1s