
"Semi-automatic" refers to the action of the gun, or where the next bullet comes from. There are about a gajillion moving parts in these guns, which is why you have to keep them clean or they jam on you like crazy. I am going to take some indecent liberties with explaining how they actually work, mostly because i am not sure i fully understand it myself and i like to refer to the process as "magic." Basically you load the gun by slapping the magazine into the hole in the bottom of the grip.

You pull the slide back to chamber a round . . .

and then you point the firearm at something you wish to puncture and pull the trigger. The bullet is fired, just like when you pull the trigger in a revolver, but the gas from the round pushes the slide back on a semi-auto handgun. The slide blows back and ejects the spent shell casing. Once that happens, the (very strong) spring in the magazine pushes the next round up into the chamber. Just like that, you're "automatically" ready to fire again, as many times as there are rounds in the gun.
Here is an exploded view of a semi-auto:

Oh, and a terminology thing: "Semi-automatic" simply means you have to pull the trigger one time for each bullet. "Fully automatic" means you can theoretically pull the trigger once and then hold the trigger down and spray bullets all over the place. Fully automatic handguns don't exist outside of that dumbass "Underworld" movie because they would be absolutely uncontrollable, and because you would be out of ammunition in like 2 seconds.

I don't mean to give a political commentary, but sometimes you do hear legislators talking about restricting semi-automatic guns. It baffles me a little as to why, or what crime that would prevent. I know people who can fire revolvers every bit as fast, or faster, than semi-automatic handguns. So it's not really a speed-of-fire issue . . . Legislation of this type is probably proposed by well-meaning people who think that "semi-automatic" sounds scary and so it should be taken away. This is why i am such a big proponent of people learning to shoot. After you have pulled a trigger a time or two, you learn that a gun is not something to be scared of. It is simply a tool. Nothing more, nothing less. Dismounting soap box now.
You don't have to cock the hammer on a semi-auto, generally speaking. They are all double-action. Some of them (Glocks, etc) don't even have an exposed hammer, so you're SOL if you want to fire it single-action. You can cock the hammer if you want on those that do have a hammer, and you see it done a LOT in movies or on TV, but it is pretty much a useless gesture. Just takes "I want to shoot you" to "I REALLY want to shoot you."
Semi-autos are pretty much the concealed carry gun of choice for most of us who carry. Basically we want as many bullets as we can get, available as fast as we can get them, and semi-autos fill this bill pretty well. I will get into that a little more in a separate blog entry, mostly because i have to go to work again. :(
I kind of blew through this entry, and i really really need some coffee, so let me know if there is anything you would like to know more about! I can address it in the comments or edit the entry or whatever.
But i will leave you with some awesome photos I found. :)




These are pretty fugly even by my standards. And the one with the snakeskin grips is EXPENSIVE, like 4-digit even before you pimp it out. Kind of ironic that guns are considered to be a redneck/yokel/poor bumpkin kind of thing, eh? ;)