When i WAS sixteen, I aimed at a very nice buck that I had been scouting for months, and didn't even notice the stout branch that was to suffer the wrath of that 8mm bullet. I had a hard lessen on scope parallax trajectory, line of sight, etc.
Maybe that is why, I hunt my own property. I have narrow shooting lanes cut across the ravine, with marks for range along each lane. I don't need a rangefinder. The only variable I don't have alot of control over is the wind. If it is still, I would take a long shot, if windy, only close shots. But without the prep work, knowing the bullet drop and range, and judging the wind speed and direction, I would limit my shots to 50 yds, maybe less.