I don't know but I suspect the reason it is 8x is so that you can use it as a viewing device (monocular) also. Since it ranges out to 400 yds you can get a better look at what you may shoot while you are getting distance. If there was a rangefinder just for bowhunters it would probably be 2x and only range out to 75 yards maybe. But that is probably not worth it to make for anyone.