Como funcionam as metralhadoras

Autor: 
Tom Harris

Some historians consider the machine gun one of the most important technologies of the past 100 years. She gave the brutal and harsh tone of the First and Second World War - and most of the wars that occurred thereafter. With this machine, a soldier can fire hundreds of rounds per minute, mowing down an entire platoon in moments. The armed forces had to develop heavy equipment like battle tanks, only to resist this type of barrier.


Photo courtesy Department of Defense American Marines fire an M-240G machine gun during training exercises at Marine Corps Base Camp Lejeune, North Carolina. Medium machine guns such as these are an essential element of modern arsenal.

Remarkable feat of precision engineering, machine guns are actually surprisingly simple. In this article, we will see the mechanisms that use guns to spit bullets with such a violent speed.

Knowledge of ballistics: Pipe
To understand how guns work is important to know something about firearms in general. Nearly every weapon is based on one concept: the application of explosive pressure behind a projectile to launch it by a pipe . The oldest and simplest application of this idea is the cannon .

A cannon is just a metal tube with a closed end and an open. The closed part has a small hole to the cap. To load the gun, arises powder (a mixture of charcoal, sulfur and potassium nitrate), and a bullet. The powder and the bullet are the yoke , the rear of the hole which is opened in the cylinder portion. To prepare the gun for a shot, raises the cap (a piece of flammable material) through the hole, so that it reaches to the gunpowder. To fire the cannon, lights the fuse. The flame passes through the fuse and comes in powder.

When firing the gunpowder, it burns quickly, producing many gases. These gases apply much pressure on the side where the powder is that the air applies to the atmosphere on the other side. This pushes the cannonball out of the gun at a great speed.

The first handheld guns were essentially miniature cannons; was loaded with some gunpowder, one steel ball and lit up the fuse. Over time this technology has given way to weapons activated by triggers such as a flintlock and percussion cap .

A gun with percussion cap (left) and a flintlock (right). To learn more about these weapons, read How Flintlock Guns Work .

The flintlock rifles ignite the gunpowder producing a tiny spark, while percussion caps used mercury fulminate, an explosive compound that can be lit with a sharp blow. To load a percussion cap gun, puts up gunpowder in the breech, the projectile over everything, and a capsule of mercury fulminate over a small nozzle. To shoot it is necessary to cock the hammer and pull the trigger of the gun. The trigger releases the hammer, which moves forward toward the capsule. The capsule lights, shooting a small flame down the tube to the gunpowder, which explodes and launches the projectile out of the barrel. See How Flintlock Guns Work for more information on these weapons.

Knowledge of ballistics: Cartridge
The next big innovation in the history of firearms was the bullet cartridge . Simply put, the cartridges are a combination of a projectile (bullet), an explosive (gunpowder, for example) and a capsule (explosive cap), all within a metal package.

Needless to say that the cartridges were a fenomental success. In fact, they are the basis for most modern firearms. In the next section we will see how these weapons work.

The backward movement of the bolt also activates the ejection system . The work of removing the ejector is used capsule extractor and put it out for a ejection port.

Handguns
In the previous section, we saw that one cartridge consists of a capsule, a propellant and a projectile, all in one package metal. This simple device is the basis of most modern firearms. To see how this works, we see the pattern of a double action revolver .

Click the trigger to see how a gun shoots

This gun has a revolving cylinder with six breeches for six cartridges. When you pull the trigger on a revolver, several things happen:

  1. Initially, the trigger lever pushes the hammer back;
    • when it moves backwards, the hammer compresses a spring metal in the butt of the gun;
    • while the trigger rotates the drum to the next breech chamber is positioned in front of the barrel of the weapon;
  2. when you pull all the trigger back, the lever releases the hammer;
  3. a compressed spring causes the hammer to go forward;
  4. the hammer hits the percussion cap at the back of the cartridge, igniting the fuse;
  5. the fuse triggers the explosive;
  6. explosive shoots the bullet out of the gun at high speed.

The inside of a pipe has ridges , spiral ridges which serve to rotate the bullet as it leaves the gun. This gives more stability to the bullet as it flies through the air, increasing its accuracy.

When the explosion occurs, the cartridge expands and closes the breech temporarily, so that all expanding gases are pushed forward and not backward.

Revolvers, which can be of various designs and sizes, are one of the most popular weapons ever designed at all times. Your design is so simple that they hardly fail to catch or shooting.

Obviously, this type of weapon is easier to use than a flintlock or percussion cap weapon. Fit six bullets at once, and you only need to pull the trigger to fire. But there are still limitations: it is necessary to pull the trigger for each shot, and reload after six shots. And Empty cartridges are removed from the cylinders manually.

Now we will see how gun manufacturers have dealt with problems typical of revolvers.