If you are talking about short range, with quick game, or enclosed areas (lots of brush, trees, etc) Then I prefer open sights, better target aquisition speed, and also you can better see what is coming up when an animal is running. If you are staying under 100 yards, and are talking about anything the size of a coyote or bigger, iron sights will do the job just fine when going for the kill shot. If you are talking about huge trees and open forest, or plain and grassland, where you have time, then sometimes a scope will help to make sure it's the exact shot you want everytime. It really depends on what you are doing, sometimes my scope makes me mad because little critters are quick and I can't get a crosshair on them, so I just take my scope off right there in the field.