Because No One Demanded It: The Internet Movie Firearm Database.

[RJBowman]

Yes, this is a real thing; a Wiki style database dedicated to cataloging who used what gun in which movies and TV shows:
http://www.imfdb.org/wiki/Main_Page

I found it when I was looking for the kind of derringer that Paladin used.
http://www.imfdb.org/wiki/Richard_Boone

[Mme. Ratchet]

My favorite website ever!

[RJBowman]

It even includes fantasy guns:
http://www.imfdb.org/wiki/Star_Wars

[Mme. Ratchet]

Yup! I use that site waaay too much.

[Burgess Shale]

This is a fun site. I was watching a Thin Man movie a couple of weeks ago and used the IMFD to verify a gun used in the murder. They even have firearms used in animated films and programs as well.