Please click the READ MORE below to read the details of this article.  At the end of the article is the video portion of the webcast


 by Jessie Indracusin


Many people who have owned firearms for years don't even fully understand the answer to this question.  The question is what is the difference between SA, DA, SA/DA, DAO trigger types?  I am going to do my best to explain it here.  Since I was at a bit of a loss for what to do for photos to discribe this, I will let the video explain this from a visual standpoint.

Single Action (SA)

Single Action means the pull of the trigger performs a SINGLE action.  Simple huh?  Well what does that exactly mean in a firearm?  Most pistols have a traditional hammer on the back of the gun.  A single action pistol requires that this hammer be "cocked" back first.  After it is in the set position, the pull of the trigger will perform the single action of releasing the hammer and causing the gun to go off.  Most single action guns will return to this hammer back position with each follow up pull of the trigger.  This means you have to only pull the hammer back once until the gun is empty.

Double Action (DA)

Double Actions means the pull of the trigger performs TWO actions.  That means instead of the need of having to pull the hammer back to put it in a set position, a single pull of the trigger both manipulates the hammer and causes the bullet to leave the gun.  Double Action mode is very common in most semi-automatic and revolvers.  The dowside of Double Action is since the "weight" of the trigger pull is so heavy, the chance of hitting a target at long range with the handgun is a bit more limited.

Double Action Only (DOA)

Double Action Only means the pull of the trigger will ALWAYS perform TWO actions.  The pistol will always have the very heavy trigger pull and the gun has no ability to have a light trigger release since it is forces to manipulate the hammer everytime.  This is NOT common in semi-automatic pistols at all.  Typically, you see this in revolvers mainly.

Single Action/Double Action SA/DA

This is the most common mode of modern pistols.  The gun has the option of a long pull (meaning the hammer is not pre-cocked and you are doing a Double Action pull of the trigger) or a short trigger pull (where the shooter has manipulated the hammer back already).  Nearly all modern H&K pistols use this type of system.  There are some exceptions to this with the PSP and P7M8 and P7M13 (which if you own a P7M13 and don't want it anymore, tell me how much you want to sell it for).  Any modern firearm with a hammer, will typically be an SA/DA gun.  

Pre Set

So how do you explain one of the most common guns, a Glock?  Well technically a Glock is none of the above.  A Glock has a two stage trigger which you can almost explain as an SA/DA mode, but technically it is not.  The gun remains in a "partially cocked" mode.  When you pull the trigger, you are completing the operation of the shot.  Is this safe?  It is completely safe, just a little different.  Unlike Hollywood movies may want you to think, dropping a loaded Glock will NOT GO OFF!  Okay, I lied.  It can still sort of go off if by some unlucky chances the trigger gets caught on something as it drops.  The chance of this is pretty low.  However, there has been a case where a criminal pulled a Glock from his waistband which caught the trigger on his clothes and made the gun accidently go off and shoot himself in the thigh (there was a chance of him hitting something a little more valuable).  


Pretty much purchase a gun that is either SA/DA or Pre Set.  Unless you are getting into "Cowboy Shooting" (yes, there is such a thing), you should always get a gun in SA/DA or Pre Set.



Last Updated (Sunday, 14 December 2008 16:49)