User blog comment:JoeRamirez/Call of Duty Modern Warfare 3 Weapons Wishlist./@comment-173.3.251.102-20110706215037/@comment-1630756-20110706220936

That's because guns are made and patented by the manufacturer; to include guns that are made after a certain year the developer has to pay royalties. Whilst your average CoD player will notice these things, in games like Uncharted people generally just want to play. (I think).