[Servant of the Nine]

56 feet at 900 yards? The must mean "inches".

You have to be right. That is a very hard shot, but he would have to be using a crossbow to get 56 feet of windage.

So9

[Servant of the Nine]

Not to contradict myself, but with a time of flight of around 2 seconds (say 3,000 feet at an average 1500ft/sec.) that could be the actual vertical drop of the bullet.
Gravity at 32ft/sec/sec gives 16 feet in the first second around 40 in the second.

So9