The Shotgun is a weapon attachment in Real life, Call of Duty: Modern Warfare 2 and Call of Duty: Modern Warfare 3. It is an under-barrel pump-action shotgun compatible with all in-game assault rifles. It is attached in a similar manner to the Grenade Launcher.
The shotgun shell in real life. Note the S Magnum on the left and the P Magnum on the right.
5 shotgun shells in real life. Note the gold ones with Shotgun Shells
It is attached to M16 and other weapons. It is used by All factions in Call of Duty Modern Warfare 2 and Call of duty Modern Warfare 3. It was the shotgun Masterkey in Black Ops.
M16 with shotgun. Note the ACOG Scope to M16.