The reason I'm a bit 'on' about this is that around here it's common to hear legislators pick up on details that could potentially become law that make good sound bytes but are not based in reality. Banning specific calibers is something already done here. Here are four cartridges of virtually identical calibers. A 9mm is a .355 and a .38 Special or .357 Magnum are exactly the same bullet at .357 diameter. In that case the difference is the length of the cartridge case and amount of powder in it. Even though there is only a fraction of an inch difference in diameter the design and function a very different. I thought the pic made it evident. Left to right FMJ ball, 9mm expanding hollow points self defense, .357 self defense expanding hollow points and .357 soft lead with a partial copper jacket game load. All very different but virtually the same caliber - from a layman's p.o.v. In .45 same exact thing below but here you can actually see the bullets themselves. The two on the left are .45 ACP ball and the two on the right are .45 Colt lead. Literally, a completely blind person could tell the difference between a cartridge loaded with a bullet and a blank that does not have one - hence the criminally negligent incompetence of the people responsible for the weapons on that set. The lead bullets on the right are hard cast, meaning a lead alloy designed so that they stay intact and not expand no matter how much gunpowder you put behind them with minimal lead streaking the lands and grooves of the barrel. Not intended for hunting. Inexpensive and great to target shooting, plinking etc. Very likely something of that sort killed the poor lady - likely to pass right through a person, especially a slightly built one. A 19th century revolver using a .45 Colt would be pure lead and loaded to a much lower velocity because the firearms couldn't take the pressure and pure lead comes apart with too much powder behind it. Get it just right and it does tremendous damage to a human body of any size. A bullet is just the projectile, a loaded cartridge consists of a case + primer + powder + bullet. This shows the expended primer with a firing pin mark in it and how it fits into the case pocket. You can see the hole through which the explosion of the primer gets to the gunpowder in the case.