Also of note: Spears fly over walls. I lost a dwarf by the name of "Useless" when a spear went to high and struck him in the heart (literally).
Thank you Useless. You have contributed more to science than you ever did to the fortress.
EDIT: Two things to note.
1: I constructed 5 railways, 5 long each, ending in a ramp and wall. 5x roller length on all of them, so 5 identical launching platforms. Firing iron minecarts, they all achieve the exact same flight every single time. Additionally, an alder wood cart went the exact same distance.
2: The Nanny Goat's left eye skids along the ground, bruising it!