Sorry that this is such a newbie question, and I'm wracking my brain trying to figure out how to do this... Right now my new carbine (Colt 6400) is equipped with an A3 carry handle. I don't plan to switch this out for a while for something like a Troy BIUS and an Aimpoint due to funds. So, since I don't really expect to do much shooting with this at ranges over 200 yards it seems like it makes sense to zero the sights at 50 yards so I don't have to make too many adjustments for range. How would I go about doing this?