I asked the same thing when I first started looking to upgrade from iron sight to a great Hawke weapon scope. This guide should give you certain insight into getting the top focus out of your Hawke scope, or any other changeable parallax scope for that...

A great general rule is the extended the lens, the extra powerful the scope. Magnification bends light rays utilizing a number of lenses within the scope, the higher number of lenses equals more power. A short low powered gun sight incorporates lower...