Does it have an extra stadia wire (horizontal crosshair) for judging distances, that works in conjunction with different sized animals on the power adjusting ring?
Mine also has an external elevation turret, marked to 500 yards or so. It works. Keep the rifle it's on zeroed at 100 yards and use the elevation turret. Checked it many times at 100, 200 and 300 yards and it's always been repeatable.