Shotgun

A Shotgun, also known as a scatter gun, is a type of firearm which does not fire bullets, instead most commonly firing multiple pellets from shells, which disperse after exiting the barrel, giving a wider shot placement area. The number of pellets on each shell varies with the manufacturer, but usually it always has at least 7-8 pellets/shell. Arguably the most detrimental disadvantage of shotguns is the limited range. Another common form of ammunition used with shotguns is the “slug”: a solid piece of lead similar to a large bullet. This ammunition has slightly better ballistics and thus slightly more accurate. Modern shotgun manufacturers even produced a rifling tool which allows the barrel to be rifled, and as the result increases the shotguns accuracy and effective range, but it will only work on slug rounds

In-Game
The shotgun is seen in roughly 4 games, but the earliest model is seen in Call of Duty 2, the Trench Gun. Several models are seen in Modern Warfare. All shotguns seen in the Call of Duty series are pump action shotguns with the exceptions being the M1014 (semi-automatic) seen in Call of Duty 4 and the Double-Barreled Shotgun in Call of Duty: World at War which has a break-action mechanism. Shotguns are the only weapons with firing mechanics which have been altered to fire several lightly-damaging pellets at the same time which spread out, even when aiming down the sights. The bullets are also unique in that they have a limited range and as such cease after a certain distance. Other weapons' bullets (even the Skorpion) when fired, have an endless range. Most of the time in the game the trench gun is a one shot kill up close. On multiplayer maps they are useful as they are deadly

Shotgun Tactics
Shotguns should NEVER be fired down the sights. Aiming down the sights ACTUALLY INCREASES the spread of the shot, as well as reduced walking and aiming speed, so should always be hip-fired. A shotgun user should always stick to close-range encounters; tight hallways, indoors, etc., and generally avoid even medium-range encounters unless the shotgun is tricked with the Grip attachment and can confidently hip-fire. Relying on your Pistol at longer ranges is a, but useful tip. The simplest way is to take dead enemy player's weapon; stick to submachine guns, and assault rifles, as machine guns may hinder your speed and sniper rifles are too long ranged. A shotgun user must change it's route every time to avoid getting noticed and killed by multiple enemy players who know where you are now. The shotgun can be a mixed blasting; it's prized for it's firepower up close, but it's reload time is sure to backfire, especially when you choose an M1014 as your primary weapon, and getting surrounded. Reloading even a single shell can and will give them time to kill you, so it's always recommended to have Sleight of Hand as your Perk 2.

Games with Shotguns

 * Call of Duty 2: M1897 Trench Gun
 * Call of Duty 3: M1897 Trench Gun
 * Call of Duty 4: Modern Warfare: W1200, M1014
 * Call of Duty 4: Modern Warfare (Nintendo DS)
 * Call of Duty: World at War: M1897 Trench Gun, Double-Barreled Shotgun,
 * Modern Warfare 2: M1014, Remington 870, SPAS-12, Striker

Video
Shotguns in action.

http://www.youtube.com/watch?v=7WIteICViiE