User blog:Failhappy/Iron sights on BO

it seems to me from watching all the BO vids i can find that most the ARs and the m60 have the same iron sight that looks similar to the FAMASs from MW2. so i was wondering if they where just there until treyarch modelled the right ones or customisable iron sights?. i dont think you should be able to customise iron sights if thats the case but what are your thoughts?