Man, if I had a dollar for every time I visited Wikipedia and said to myself, "There really aren't enough pages about guns in movies on this site."
Thankfully, someone heard my internal plea and created The Internet Movie Firearms Database, a catalogued repository of every time a gun has been used in a film.
Want to know what specific weapons were used in "North by Northwest"? Want to know how many films a Degtyaryov DP Series Machine Gun has been featured in? IMFDB has you covered.
The site also covers television, anime and video games, but for our purposes, we just wanted to know what Patrick Bateman used to live out his murderous, psychotic fantasies. And now all is right with the world.