User blog comment:Carbonite 0/MW3 Real Life Achievements/@comment-75.158.175.91-20120215010740/@comment-3140952-20120216182939

Meh, considering each missions takes between 10-20 minutes once you get the hag of them, it's not unreasonable to think it takes 4-5 hours on vet (if you really have the time to do that in one sitting).