One of the hallmarks of the true sportsman is the discipline required to turn his nose up at marginal shots. The other is to taking the time to make the shot. The whole idea is to get close, put them down with one, and end them fast and clean. Save the challenging difficult shots for the range.
In fact, there is only one animal where Hail Mary shots may be warranted, and dirty deaths are warranted. But that one walks around on two legs, and often has guns of his own.