Using Rain Gun in farm

Hi , I would like to know the about Rain gun if any one has experience using it. I will be using it for horticulture crops for next two to three years as i am setting up newly.

  1. Experience with using Rain Gun and any specific disadvantages
  2. I am planning to use 30 meters Rain gun. Any recommendation on best Rain gun to use which is available in Karnataka
  3. I have 180 feet casing borewell and planning to use water through rain gun at least for 3 acres . So any recommendation on the HP of motor to be used.