Shotgun (attachment)

The Shotgun is a weapon attachment in Call of Duty: Modern Warfare 2. It is an under-barrel pump-action shotgun known as the Masterkey, based on the Remington 870MCS developed originally for the M16 assault rifle. It is attached under the barrel of a weapon in a similar manner to grenade launchers.

In-game
In Multiplayer it is unlocked for Assault Rifles by getting 20 Kills with the mounted grenade launcher. It is pump-action with a four round magazine, and a capacity of 20 shells. If put onto a weapon with limited close quarters effectiveness like FAL, FAMAS or M16A4, or a weapon that has a small magazine, like the SCAR-H, the custom class becomes more versatile while still allowing for a secondary weapon. This attachment is relatively rare and allows the user to surprise enemies due to its infrequent use. It is also faster to switch to this attachment than it is to switch to a secondary weapon other than a handgun. Unlike most secondary shotguns which fire eight pellets per shot, the Masterkey fires only six pellets. Players should notice that the crosshairs grow larger when the player is moving, unlike other shotguns. This is unusual because none of the other shotguns lose hip accuracy while moving. This shotgun has by far the longest range of all of the shotguns, with its pellets traveling more than double the range of the Model 1887. However, at such ranges it will take multiple shots to kill a target, making it fairly ineffective. The Masterkey benefits greatly from both Stopping Power and Steady Aim.

Trivia

 * It is most likely intended to be a KAC Masterkey, although other companies such as Ciener and Serbu produce similar items.
 * The correct use of the Shotgun is to use the magazine of the rifle as a grip, and to pump with the other hand. This of course would make it unusable on bullpup weapons.
 * Every time the player switches to the shotgun attachment from the weapon it is attached to he cocks the gun. In reality this would eject a round, wasting ammo.
 * As of 2016, the US military will not be using the Masterkey, but instead the M26 MASS, as it is magazine fed, more comfortable to fire and offers more versatility.
 * A good tactic is to use the Masterkey Shotgun on any assault rifle, when secondary weapon is a launcher, especially the Stinger, because the player will lose usefulness in close combat as the Stinger as a secondary means that a shotgun/machine pistol cannot be used.
 * It is a good idea to attach this to a medium-ranged weapon, so you can use this in close range, saving you rifle ammo.
 * This is often contrasted to the M203 as grenade launchers have range, but the Shotgun has almost the opposite, close range firepower.
 * In Campaign mode the shotgun holds a total of 7 rounds before reloading. While in multiplayer it has 4 rounds before reloading. This was probably done to keep this from being overpowered.
 * If this attachment is used in conjunction with Bling and FMJ, FMJ will not apply to the shotgun.
 * It is much more shorter than its real life counterpart.