There is no, scale to weapon ranges in this game. It is all subjective, which is fine by me. Just because a weapon can fire a certain distance doesn't mean it will be used at that range in real life.
I'll use my favorite time period as a example. The Henry Martini rifle used by the British during the Anglo-Zulu War had a range of 1,000 yards. But, it wasn't really very effective beyond 400 yards. Plus the lay of the land, the fact the smoke from the weapon would get in the eyes of the soldiers, and the fact the Zulus knew to wet their shield and hold them to deflect bullets at a distance all contributed in the weapon not really being a terrible killing machine beyond 200 yards in many battles. Thus, as a game you could make the case to keep the range much shorter than the weapon could fire.
Same is true of all weapons. A game designer can either go with cold facts or game play. In this case MP chose game play, and I for one am glad they did.
I know that sound odd coming from me. But, I believe there is a balance to be met. I may disagree with the balance when it comes to stats such as kill, target, and armor ratings, but not so when it comes to ranges. After all, we do not play to scale, with our terrain to figure height either.
Best to you.