I am a Brazilian fan of your books and a I have a question for you, who so deeply study the history of war and strategies.
Why did take so long to the adoption of the cartridges gun shells? Since the development of the first fire guns  it took almost 500 years for the cartridge to be accepted.
I’ve read that there are historical registers of some cartridges ancestors in the XV or XVI century, used by the Netherland’s king’s forces and wonder what has gone wrong with these beta testers, once the rapid fire seems to be a great advantage in combat.
Pedro de Assis