Look at the back of the breech. If there isn't a hammer, it's hammerless. Hammers are those things that stick up at the back of the barrel. On a single action gun you have to cock them (pull them back) before you pull the trigger. Pulling the trigger cocks and releases the hammers on a double action. All the firing mechanism is inside a hammerless gun.
Mechanical action.
To cock a gun means to load it sort of. Like, when you hear guns go like -chk chk-. When you cock a gun, you are placing the hammer in a position to fire the weapon.
Cock it? I think you just shoot until it runs out.
You only have to cock it if it is a spring gun.
500 or so
Mechanical noise
by pulling the hammer back.
sear
May be a hammer or a striker, depending on design of the gun.
A spring gun? It depends on how fast you can cock the gun. There is not a fastest gun.
when was a gun exactly made from strach