Regarding the .32 (ACP) - in my dumber youth I fired half a box of .32 ACP's through a 103 year old Iver Johnson .32 (S&W) topbreak revolver (I know, I know. I'd never do it again, although the gun did hold up. I was like "Hey! They fit!"). Some of these were fired at a typical 55 gallon steel drum. They did go through one side, making a nice, oval hole, and bounced off the other, falling into the barrel. I don't know how much velocity would be lost firing the .32 ACP through a semi auto gun for which it's intended, if any at all. But plain jane FMJ .32 ACP's will penetrate at least one side of a steel oil drum. Just FYI.