Safest way? Country park, find an earth backstop, shoot to your heart's content
Come to think of it, I went to a kite flying country park last year. Even on a windy beautiful weekend day, there was enough open space that I could have safely set up a target on the edge of the trees and not really scared anyone. There were tons of other open fields where nobody was flying kites--just empty space. Are there a lot of parks like that in NT?