Most firearms can be organized into two groups: Handguns (pistols) and Long Guns (shotguns and rifles). Pistols are smaller and can be held in one hand, but shoot powerful rounds (enough to stop large game). Pistol size has little to do with the size of ammunition they can shoot. Pistols shoot one bullet (which is part of the “cartridge”, or “round” of ammunition) every time the trigger is squeezed. It must be reloaded–or can have up to 10 rounds loaded for more rapid fire. Revolvers are one type of pistol; they have a cylinder, and chambers that revolve to place a fresh round under the hammer, ready to be shot. Semi-automatic pistols have a magazine that slides into the gun. A spring in the magazine keeps pressure on the rounds, so that when it is fired, empty cartridge is ejected out of the pistol, the next round in the magazine is pushed up into the chamber (Semi-automatic means that you have to squeeze the trigger once for each round to be fired, and the next round is automatically loaded into the firing chamber each time you fire). Revolvers are generally easier to operate, and are much less likely to jam than semi automatic pistols–but they don’t have as many rounds as semi-automatic pistols.
A shotgun is a long gun that is often associated with hunting and sports shooting. Shotgun ammunition is referred to as a “shell”; it holds BBs, larger pellets called buckshot, or slugs that are propelled out of the shell when it is fired. The number can range from hundreds of small BBs–good for hunting birds, which is why it’s often called birdshot–to one big lead slug. Shotguns fall into three types of action: single or double barreled guns that must be manually loaded for each shot; pump or lever action shotguns that hold multiple shells and must be manually operated between each shot; and semi-automatic shotguns which function like semi-automatic pistols.
Shotguns are more powerful, generally speaking, than handguns, and are generally easier to operate. However, it is heavier, and has more recoil (that’s the force that pushes against your body after you shoot a round) than handguns. You must be able to hold the gun steady long enough to shoot to stop the threat, and to take the recoil as it is fired.
Rifles are useful in hunting, and for certain situations (such as defending a home or business from people outside, when accurate long-distance shooting is important). They can shoot small caliber ammunition the same size as handguns, or cartridges so powerful they can disable a vehicle. These guns are very popular in military action, because of their power and accuracy.
Rifles generally aren’t recommended as personal defense weapons; they’re too powerful for the distance that most attacks happen within. The bullet could pass through the bad guy with minimal damage, and continue for long distances, going through other areas and walls, possibly injuring innocent people.