Is it just because brass is reloadable? But what makes it reloadable? What does brass bring to the equation that the steel cased ammo can't do?
When 9mm was short I bought some steel Tula ammo, it was cheap and available. When at the range I was shooting it and it sounded different and felt different, way less kick. So I loaded up a mix of Tula and some Federal. Big difference between them. I also had failure to eject on the steel, then put brass in and did not have that problem. I do not buy cheap steel ammo anymore.
Ok folks, BOTH Brass and Steel work harden. That's what happens when you get into the plastic deformation part of the stress - strain curve. In the case of brass it can take significantly more deformation before it hardens than steel, steel can take significantly more stress before it goes into plastic deformation. Steel is unattractive in plastic strain environments because it has an unstable plastic deformation region before it stress hardens. Brass has much smoother performance. I don't know a heck of alot about making casings, but certainly for necked casings steel will wear out tooling much faster than brass. In a straight wall case it probably doesn't matter as much since it is just tubing. Typical Brass has a brinnell hardness of around 60, mild steel around 130. Steel is a LOT harder than Brass. Thinkingblade
Brass is slightly softer than annealed steel. Both can be reloaded, once or maybe even twice. But STEEL has a tendency to WORK HARDEN, becoming brittle. Which is why it's used for tools and other applications where work hardening is a plus. It's actually designed to do that. Brass does not work harden, because it is a different sort of metal. That's the main reason.
