When he shot blanks in the movie he had to rack the slide to rotate the cylinder and cock the hammer for each shot. The Fosbery was also used as a murder weapon in "The Maltese Falcon". Sam Spade's partner was killed by WITH one at the beginning of the movie.
Let me start by saying that I know what I'm about to write is a tad petty,
but when we say things liked killed
by a gun we play into the hands of the anti's who do their best to demonize the evil firearm. It's an inanimate object. A gun never killed anyone. The person holding it did.