Types of Guns (Defined)

PISTOLS

When people say PISTOLS, it is also referred to as HANDGUNS. As for the FBI Uniform Crime Report System, they are defined as something else, in other words they are also known as semiautomatic which is often called automatic when it really isn't. "Both automatic and semiautomatic handguns are loaded with cartridges by first loading a container called a magazine, or loosely called a "clip", then inserting the magazine into the grip (handle) of the gun.  Such magazines can be made to hold a gazillion cartridges, but the ones that come with the handguns have limits of anywhere from five to 19 cartridges."

REVOVLERS

A revovler is a LONG gun in that rifiles (LONG TYPES OF GUNS) have been built using a cylinder to hold the cartiridges

DERRINGERS

A type of "handgun"  that is very small and short. It has one barrel or often two barrels together in one barrel structure that hinges that go down in front to enable the cartiridges to be loaded directly into the end of each barrel. Such guns have been built with several bores.  The design is named after the inventor or an early maker of such guns, although with a spelling error.

RIFLES

Rifiles is a gun that is designed to be held in two hands and has a barrel over 18 inches long and a "stock" that rests up against the shooter's shoulder when the gun is fired.  This stock helps to steady the firearm so that it can be aimed more accurately than a handheld firearm.  The firearm name comes from the treatment called "rifling" on the inside of the barrel.  This is a set of grooves that spiral down the length of the barrel.  These grooves cause the projectile to spin along its flight from the gun to the target.  This spin causes the projectile to fly straighter.

 SHOTGUNS

A shotgun is a long gun that looks somewhat like a traditional rifle on the outside.  But a shotgun is usually used to shoot a packet of "shot," like little beads.  Because of what it shoots, the inside of a shotgun barrel is not usually "rifled."  If the gun is used only to shoot big chunks of lead, called "slugs," the barrel may be rifled.  Most shotguns, however, are designed primarily to shoot the "shot" and, if the gun is used to shoot slugs, the slugs themselves usually have the grooves to cause the slugs to spin as they come out of the barrel.

 SEMIAUTOMATIC FIREARMS

A semiautomatic firearm is one that shoots one cartridge each time the trigger is pulled, but uses energy from the firing of each cartridge to eject the empty case and insert the next cartridge into the firing chamber of the gun.
 
MACHINE GUN  

A machine gun is a fully automatic "rifled" gun.  A fully automatic gun is one that shoots cartridges--usually rapidly--as long as the trigger is held.  For handheld guns, the term "machine gun" is usually used for rifles only, although there are "machine pistols."  Some (usually larger caliber) machine guns are mounted on or in tanks, aircraft, etc.  Some used by the military are mounted on tripods for field use.  A machine gun rifle that shoots cartridges of calibers that are normally used in handguns is called a sub-machinegun.  The old Thompson sub-machinegun ("Tommy gun") seen in war and prohibition era gangster movies is the most common example of this. 

BOLT ACTION

 Many rifiles & few shotguns use "bolt action" when inserting a cartridge into the firing chamber of the gun. The "bolt" is a nearly cylindrical rod that fits in the gun behind the firing chamber,  it has two tabs that stick out into channels in the gun frame, and these tabs turn into cuts off to the sides of the main channels to lock the bolt into position when the bolt is "closed" behind the cartridge in the firing chamber.The bolt then pushes the cartridge into the chamber, and is then turned to lock in place and make a totally enclosed firing chamber except for the bore of the barrel in front of the cartridge.  Turning the bolt back, then pulling the bolt to the rear, pulls out the cartridge or the empty case and ejects it. A handle that sticks out to the side of the bolt near the rear end is used to move the bolt in and out and to turn it into and out of the locked position.

 

PUMP ACTION:

Numbers of rifles and shotguns use "pump action" to enter and eject cartridges and cases into and out of the gun firing chamber.  The "pump" is under the barrel out in front of the trigger when a cartridge/case is not being moved.  There, it serves as a device to hold the gun and steady it the same as gun stocks on some guns.  To eject a case and load the next cartridge, the pump is pulled back as far as it will go toward the rear end of the gun, then pushed back out to the far position. 

LEVER ACTION

 Lever action is mainly used on rifles, very few shotguns have it as well.The lever is located under the trigger and a bit behind it. Part of the functions help it so that you don't pull the trigger by accident. The lever hinges at a point forward of the trigger.  To eject a cartridge or empty case from the gun firing chamber, the rear (handle) end of the lever is pushed forward.  Bringing the lever back into the firing position loads a cartridge into the firing chamber, if the gun magazine was not empty, and cocks the hammer so that the gun is ready to fire again.  The lever action rifle was the first "repeating" rifle and appears in "western" movies about the cowboys, cavalry and indians

ASSAULT RIFLES
An assault rifle is a rifle used by militaries.  It has a switch that permits it to fire like a semiautomatic rifle or as a fully automatic rifle.  Some also have a switch position that causes the gun to shoot a short burst of several shots each time the trigger is pulled.  Compare to what laws and gun control advocates call assault weapons.

SOURCE: http://www.gunsandcrime.org/guntypes.html