Hope this helps. DA or DOA (double action, double action only) models when you rack the slide and chamber a round it will remain in the DA mode. DA/SA models, when you rack the slide it will draw back the hammer and it will be in SA mode. Now depending on what gun you have if you have a decocker when the decocker is engaged it will lower the hammer to DA mode or half cocked which will still be considered DA but with a shorter pull. If not a decocker you would have to carefully decock the hammer manually to lower into DA mode or leave it "cocked and locked" and engage the safety which will have it remain in SA mode. It would help to know which handgun you have or are thinking of getting to better give advice or to answer your question.

I'm thinking of getting the Beretta PX4 storm which does come in DA/SA. So if i were to rack the gun, it would just go into SA? the thing i dont get (and maybe its because i don't fully understand DA and SA) is if it is in SA and you fire, doesn't the gun still blow back, rechamber a round and cock the hammer? if so how is that different from DA?

wow, i just looked it up on wikipedia and now i'm even more confused.
i'm sorry to be a burdon, i'm just trying to understand it all.
so i thought i knew what things mean but i guess i don't. so here it goes:

i thought a decocker completely lowered the hammer so you couldn't fire it and then to fire the gun you would have to cock the hammer and you would be able to fire. is that right?

i thought SA meant you had to cock the hammer back for each shot. is there more to that or what?

i thought DA was once you rack the slide, the gun is cocked and for every round thereafter all you had to do was point and fire. but wikipedia made SA on semi-auto guns sound exactly the same as this.

i'm very sorry for all the questions. i just want to understand before i go out and buy.

thanks in advance.

Best thing to do for your best understanding is to go to a gun shop and ask your questions. They will have handguns there to show you what the difference is between each designation. They won't laugh at you, they'll probably appreciate your trying to get the information before you purchase something you don't want. By the way, if they rent guns at that shop, try the .40 and the 9mm, then you'll know what you would like to start with.

thanks, i'll do that

You might also consider taking a Basic Pistol course from an NRA-certified instructor. Check here: http://www.nrahq.org/education/training/find.asp.

i thought a decocker completely lowered the hammer so you couldn't fire it and then to fire the gun you would have to cock the hammer and you would be able to fire. is that right?

Yes on a SAO (single action only) pistol like the 1911, but not on a DAO or DA/SA pistol. A decocker simply decocks the weapon so it fires in double action mode. Some decockers, like on the Beretta 92FS for example, are also a safety which means the gun won't fire. But to make it fire you do not have to cock the gun, you simply take the safety off. The gun will then fire with the hammer down in double action mode.

i thought SA meant you had to cock the hammer back for each shot. is there more to that or what?

You must manually cock the gun for each shot with a single action revolver. With a SA or DA/SA semi-auto pistol, the hammer is cocked automatically after each shot by the action of the slide.

i thought DA was once you rack the slide, the gun is cocked and for every round thereafter all you had to do was point and fire. but wikipedia made SA on semi-auto guns sound exactly the same as this.

Wikipedia is more right. For either a DAO or DA/SA gun all you have to do is point and fire. On either gun when you load it you have to rack the slide to chamber a round. You are not racking the slide to cock the hammer because either will fire with the hammer down.

Here goes:

DAO (Double Action Only): The gun fires in double action mode only, meaning it is a longer, heavier trigger pull because the first part of the trigger's travel is to cock the hammer back. Only the very last part of the travel is to release the hammer. Every time the gun is fired, the slide cycles, ejecting the spent cartridge and loading a new one. On a DAO only pistol this cycle does NOT cock the hammer. Essentially the gun has an internal decocker. So, after the first shot and the slide cycles, the hammer is again down and the gun fires with the longer heavier double action pull. This continues for every shot.

DA/SA (Double Action/Single Action: The gun may be fired in double action for the first shot but then reverts to single action for the remaining shots as the slide does cock the hammer when it cycles. With the safety/decocker on, when you load the gun and rack the slide the gun will be in double action with the hammer down since the decocker was on. You simply take the safety off and now the weapon is ready to fire in double action (hammer down). All follow-up shots will be in single action because the cycling of the slide does cock the gun.

At any time, say halfway through the magazine, you can flip the decocker, and the gun will then be in double action mode for the next shot. You may fire the gun in double action, or you may cock the hammer manually and fire it in single action.

SA or SAO (Single Action Only): The gun must be cocked for the gun to fire. The trigger will not serve the function of cocking the hammer. When you load the gun and rack the slide, the gun is ready to fire with hammer back. If you manually lower the hammer, then to make the gun fire you must cock the hammer with your thumb or rack the slide in order to cock the hammer.


Hope this helps.

Wyatt,
Very good info, thanks a lot. I finally understand now!
And thank you for your time writing that up.

No problem at all and I do realize the thirst for knowledge, especially when new to firearms. However I must say that Mike's response is actually the best. Take a Basic Pistol course from an NRA certified instructor. Then you will have a hands-on understanding.

Originally Posted by Wyatt

Then you will have a hands-on understanding.

+1 Although, you did provide a good write up nevertheless.

Is the pistol course you guys are talking about the same one that I would have to take for my CCW? or is it something different?

Originally Posted by jwmahoney

Is the pistol course you guys are talking about the same one that I would have to take for my CCW? or is it something different?

Depends on the state. A CCW course should fill you in on most of the basics, though.