FPS alone doesn't determine the range.. My rifle shoots about 20-40% farther than my brothers gun which shoots around 380 fps. (mines 430) and is generally a heck of a lot more accurate. I was playing mostly as a marksman rather than a sniper in the last game which seemed to work pretty well as I could usually outrange the folks we were playing with.
And they wont wanna rush you if theres a machinegunner spotter with you. :grin: