User blog comment:Cubuff37/My Official Review Of Call of Duty: Advanced Warfare/@comment-1916935-20150131200152/@comment-3967954-20150203174656

Well, Halo isn't exactly a good example of a realistic futuristic setting; they're using 7.62 assault rifles 500 years into the future. With no sights. And petrol-powered jeeps and tanks.

No-one can really say with any certainty what the 2500s will be like, but other than space travel and super-soldiers, nothing much seems to have changed in the Halo universe. In hindsight, they probably should've set it closer to the present.