Frankly, I think that they won't. If you don't know which person you're shooting at, there is a big problem. I don't ever use the "sights" on my NF. I nail people with that thing all the time. Hitting people is a natural thing. YOu have to feel where the dart will go. I've been shooting my Nite Finder for a long time in its current state (as in, shooting it as it is currently modded). It is now an extension of my arm when I pick it up. I don't think about it. It just flows, and my arm knows where to go to hit. And it does. The same goes for my crossbow. Granted, on something like a crossbow, you can line up your shot along the crack that divides the two halves of the shell, but frankly, you'll probably end up missing more often than not.
when I shoot I dont just fire blindly I try to line up my gun with a target...Sights would give me an idea of what im shooting at.
At Armageddon, for example, out of all of the hits I got on people with my xbow, I probably only used the crack twice. Everything else, even all of my distanced shots, I snapped the gun to my shoulder, my mind's eye "saw" where the dart would go, and my finger pulled. *Headshot* In archery, this is called "Instinctive Shooting". Take some time in your backyard with some empty two-liter soda bottles set up, and just walk around. Enjoy the ecenery, and then randomly snap your gun up and shoot at one. Never spend more than about two seconds "lining up" a shot, because no enemy will ever give you that long to aim at them.