G56 said:Be careful when loading magazines!
This is what happened to someone who accidentally loaded a 40 S&W cartridge in a 45 acp pistol, this could have been much worse!
Found on the net, I don't know any more details.
The details look to be pretty evident. The brass expanded to meet the size of the chamber and it was enough to split the brass. Hopefully this happened in a well made steel .45 1911 or this could have had some really bad consequences. A .40SW is a MUCH higher pressure round than a .45ACP.
I'd amend the caution to extend to any situation where you are dealing with live rounds. You are your own worst enemy and your own best friend. Be safe everyone! =]