How do machine guns work?

Question

I just need a simple, maybe 4-5 step description. I know there are different types of machine guns, but try to make an overall one that'll explain the general process.

Thank you.

Answer 1

When a bullet (round) is fired, the gunpower explodes forcing the bullet foward and the shell casing backwards.  This energy (recoil) of forcing the shell casing backwards is used to re-c**k the gun for the next round.

Answer 2

the simplest and most common type of machine gun is gas operated.

The gas created when the bullet is fired is used to operate a piston that recocks the gun for next round.

Answer 3

The most simple machine guns use an ‘open bolt’ design opposed to the more common ‘closed bolt’ design in semi-automatics. Most sub-machine guns are open bolt, such as the UZI, Ingram M10, Sten, Thompson, MP40, ect. Open bolt semi-automatics are extremely rare and have been illegal to produce since the early 80s due to their ease of conversion to fully automatic.

Unlike closed bolt firearms an open bolt machine gun does not have a hammer or firing pin. Instead the firing pin is fixed to the bolt itself and will detonate the primer of the cartridge as soon as the bolt is pushed forward by the spring. This is why the bolt must remain in the open position until you press the trigger, which releases the sear and allows the bolt to move forward. The pressure of the detonated cartridge blows back the bolt and if you are still holding the trigger the sear will not catch the bolt and the machine gun will continuously fire until either you run out of ammo or you release the trigger and allow the sear to catch the bolt.

Most open bolt machine guns are select fire and can be switched between semi-auto and full auto firing modes. I would go in depth on how the semi-automatic mode works as well, but that wasn’t your question and actually has more working parts than just a sear.

There are closed bolt machine guns as well. The AK-47 uses a closed bolt and rather than having the sear catch the bolt, the bolt trips the sear, which in return releases the hammer without requiring you to pull the trigger again. The trigger mechanisms are slightly different in each gun of course, but the sear is what really produces the fully automatic fire, regardless to whether the gun is open or closed bolt.

Answer 4

http://science.howstuffworks.com/machine...