Slang use for penis. Much more funny to use in public because most people do not know what it means. Can be used in a lot of different contexts. Emphasis on REAL.
Look at the size of my gun bitch, you think thats somethin? Wait till I take off this latex and show you some REAL pistol.
Dude1: man this girl is texting me like crazy!
Dude2: she prob wants you to show her some REAL pistol!