Why do you need to c**k a handgun before you shoot?

Question

OK so I'm new to guns in general and I've always been curious why in any movie or tv show they always **** the gun first (I'm guessing for dramatic purposes). Is it really necessary to **** it first? Doesn't it just fire without cocking it? Does it matter if it is a revolver or a semi-automatic? I've heard the term single action and double action thrown around... what exactly does that mean?

Answer 1

The ONLY time you NEED to **** a handgun before you shoot it is if the handgun is a single action.   If the gun is a double action,  you never NEED to **** it to make it work...

SINGLE ACTION>...the trigger only does one SINGLE thing,  it drops the hammer onto the cartridge making it go off.   You have to use your thumb to **** the hammer.  

DOUBLE ACTION>...the triggger does two things.  It first makes the hammer go back then it drops the hammer on the cartridge.   You do not have to use your thumb.  

The above only applies to revolvers....

A good gunman with a single action can fire as fast as someone with a double action...  

Answer 2

Except for single action revolvers, where it's always necessary to **** the gun before firing, the movie action is mostly for effect. Double action revolvers and pistols do not need to be manually cocked to fire.