Can't speak to what could arguably be a total work of fiction referred to in that "wonderful" movie, but I have read and practiced the techniques set forth by Paul Matthews in his books concerning BPCR (black powder cartridge rifle) reloading/shooting, including paper patching bullets.
Its called "The Paper Jacket." I got mine years ago in a set with multiple books he has authored...all are excellent reads, but may (or may not) help you with the direction you are wanting to go.