Advantages of trigger action types?

[White_Wolf]

Being new to guns and all, I have no idea what kind of trigger action I should be looking for.

As far as I know, there are three types of action: Single, Double, Double Only.

Let me see if I am correct about what each one of these terms mean.

Single Action: This requires that the hammer be cocked before the trigger can be pulled to fire the gun.

Double Action Only: This requires you to do a long trigger pull, because the hammer cannot be cocked.

Double Action: This allows you to fire the gun without cocking it, or cock it for a shorter, lighter, smoother trigger pull.

Now what I want to know is why there are different types of actions. Does any one type have an advantage over the other?

Is it true with a single action revolver you can pull and hold the trigger, and then fire all your rounds just by fanning the hammer?

Do Semi-Automatic Pistols come in all three action types?

 

[Majic]

Yes semi-autos come in all 3 types.
Yes you can fan a single action, but you will damage it.
The 3 types represent the evolution of the handgun. First there was the single action followed by the double action with the DAO being last. The DAO was just an engineering attempt to correct a gun handling problem. People were having trouble with decocking guns or inadvertantly firing a cocked handgun so the gun was designed to never stay cocked. There is no real advantage of one type of action over the other. It's a matter of training and handling.

 

[TX1911fan]

There are pros and cons to each. Long trigger pulls are safer if you are worried about accidentally pulling the trigger. Short trigger pulls significantly aid in accuracy as the gun is less like to move off target during a short, light pull. The DA/SA would seem to offer the best of both, but often end up not being very good at either. It depends on the gun, your preferences, your technical skill and your training. I recently replaced my bedside gun (a SA 1911) with a double action Ruger revolver. Not for me, but because my wife does not go to the range nearly enough and I worried that the short SA pull of the 1911 would be a problem for her. I'm much more comfrtable with her having the long DA pull of a revolver. Of course, if she is certain she is going to fire, she can cock the hammer and have a very short SA pull.

 

[rockstar.esq]

A plain old DA semiauto behaves just like a DA revolver for the first shot which can allow for a "safety-less" manual of arms. That is to say that you don't muck with any levers you just pull the trigger when you want to shoot. Detractors of these guns will cite how cops getting shot with their own guns live a few seconds longer if theres a safety to disengage. Since I'm not a cop and I don't open carry, this is less of a concern for me. DAO is sort of the extension of the whole safety = DA notion. Frequently these firearms have bobbed hammers which allow for more concealable profiles. SA only Semiautos are often revered for their nice triggers. Something of a frustration to many is that the very same SA's with such nice triggers render unimpressive "combat accuracy". I have a SA target semi auto and it's tons of fun. My DA Sig P220 renders impressive accuracy without requiring a "match" trigger nor special ammo.