hey guys. i just got a new scope on a great bargain. a relative is having hard times, and he sold me VXIII 4.5-14x40 Long Range for........ $300. wht is the advantage of 30mm tubes? all my other scopes are 1'' tubes. and how does the side focus work? i have never had a scope with these bells and whistles. just plain old leupolds til now .any help would be good. thanks guys