I have pounds and pounds of WWII brass, its a lot easier to work with than this new stuff.
I believe the brass back then was harder than it is today. I took 2 pieces of military brass put them in a tube just slightly larger diameter then the case and dropped the case from 10ft. The newer caseing dented the neck like someone stepped on it. But the WWII one was fine. Didn't do much science behind it. But I do then the brass was harder back then.
If your worried about being brittle, try annealing the brass. It will strengthened the walls, neck and shoulder.