This tip relates to bullet drop.  Remember this phrase —  half, one and a half, three, and five.  This is bullet drop within a few inches for most of the popular hunting calibers at 300, 400, 500 and 600 yards when sighted in DEAD ON at 200 yards.  So…  1/2 a foot drop at 300, 1 and 1/2 feet at 400, 3 feet at 500 and 5 feet at 600 yards.  Now I don’t really recommend shooting at 500 and 600 yards, UNLESS that bull is wounded and getting away.  I use this when I have a hunter that shot at my preferred range of less than 400 yards, hit that animal,  and the animal is moving further away and still presenting another possible shot opportunity which might minimize the chance of loosing it.  This rule of thumb will definitely get you on the animal for hopefully another hit or a better hit.  No one likes loosing wounded game.