What does “Cocking the gun” actually do in movie scenes. Why wouldn’t you just pull the trigger?


What does “Cocking the gun” actually do in movie scenes. Why wouldn’t you just pull the trigger?

In: Engineering

First off, this depends greatly on the type of gun involved. I’ll break that down after I explain your original question.

A round of ammo for a modern firearm contains a “primer”. This is a little piece in the butt of the round that contains a “percussive explosive”, meaning that if you hit it, it will explode. That explosion ignites the gun powder, and propels the bullet forward.

Your gun basically contains a little needle that slams into the primer and causes it to fire. When you “cock” the gun, are pulling back the “hammer” that will hit that needle, and putting tension on a spring that will cause the hammer to move forward and hit that needle. A mechanism engages to hold the hammer back, and pulling the trigger removes that mechanism, allowing the hammer to jump forward.

Now for the “it depends on the type of gun part”. Not all guns have an external hammer in this day and age. For example, Glocks are “striker fired”, which means that instead of normal “hammer” that you can touch, it’s all internal. Meaning that you can’t “cock” a Glock, except for when you cycle the action to load a round into the chamber. So a Glock is basically “always ready to go”, and you can’t “cock” it for dramatic effect. However, you will hear cocking sounds in a lot of movies when the character is using a Glock, because it excites the audience.

In the movies, it’s show of force from one character to another. For the audience, it escalates the tension in the scene. Just pulling the trigger would not have the same effect.

In real life, cocking the gun reduces the amount of force you have to put on the trigger to make it fire.

In modern bullets the powder in the bullet is lit by a smaller explosive on the back of the casing. That explosive is set off by striking it hard. Cocking the gun pulls back the piece that strikes the round.

Also it moves a round up into line with the barrel and lock it into place.

Sometimes in movies/TV you’ll notice a gun cocking sound effect when a character DRAWS their gun, not even when they cock it. It makes no sense. The sound is really just an audible cue that “there’s a gun out now”

When a round gets fired, most of the energy is used to push the bullet out of the barrel. Some guns will use some of that energy to do a bunch of mechanical wizardry that gets rid of the bullet peel and gets a new round ready to be fired.

You can also get a round ready for firing by manually moving whatever part on the gun you need to to get that mechanical wizardry done the old fashioned way.