On powders I am really needing almost a chemists handbook. I want to know how and why the different ingredients in different powders work. I want to know how and why the different shapes to the powders exist and work, etc.
I'm also really curious about casing design. How and why exact lengths, diameters, angles, etc. were chosen and what they do for the performance of the cartridge.
Hopefully I can find materials pursuant to this.
Your 9mm could, and in all likelihood will expand. But my .45 will never get any smaller.