I picked up a mint remington 700 laminate/stainless .300 win mag today for a steal. It is topped with a vx 3 which was also spotless. My big question is that there is a ring on the front of the scope for what I would assume is distance focus? it didnt appear to have any ranging reference in the reticle but I could be wrong. any idea what this ring is? I can post pics if it would help. He had the box but no manual with it and no ident on the box.