When it comes to action movies, two guns are always better than one.

This week, Denzel Washington and Mark Wahlberg have each other's backs in "2 Guns" -- hence the name, "2 Guns." While it's always handy to have a partner in crime-fighting, sometimes you have to go it alone. And having a pair of pistols can be just as good as having a wingman (or woman).

Below, Moviefone reminds you why having double the guns can save the day -- at least when it comes to movies. From "Butch Cassidy and the Sundance Kid" to "The Terminator," it's practically action-movie law to be twice as loaded.
EARLIER: 2 Guns' Restricted Trailer: Denzel Washington and Mark Wahlberg Are Incentivized (VIDEO)

'2 Guns' Premiere: Mark Wahlberg Tells Denzel Washington to Lighten Up