MG4

The MG4 is a light machine gun developed and produced by Heckler & Koch. It was chosen to replace the heavier 7.62mm MG3 at the squad support level. It will supplement the MG3 in other roles. It is the standard support machine gun of the Bundeswehr (German army).

Call of Duty: Modern Warfare 2
The MG4 was first seen in the Art book as concept art. It was however confirmed when pictures of Create-A-Class weapon lists were leaked. It has not been seen in any gameplay footage, so not much is known about it at the moment.