Is Call of Duty rated M?

I know that Call of Duty 4: Modern Combat, and Call of Duty: World at War are rated M for Mature. CoD4 is by far the less graphic of the two, as CoD:WaW has gruesome dismemberment and copious blood. Neither of these are comparable to Gears of War though, that really earns its M rating. Call Of Duty #1 through #3 are rated T for teen.