While QI has reported that a raindrop is spherical as it falls from the cloud which created it, that's not necessarily true.
The shape of a raindrop is determined by the speed of the air it falls through.
As the water droplet falls, it's shape is constantly being altered by the wind resistance created by its fall AND by the lateral movement of the ambient wind.
This is because of the water drop's viscosity; it's very "fluid" and its shape is easily distorted by the air currents.
Lead shot on the other hand, dropped while still molten from the top of a "shot tower", plummets as a perfect sphere with little or no resistance from the air it passes through to arrive in the cooling water at the base of the tower.
The molten lead, as it falls as a sphere, cools just enough during its fall that its shape is unaffected by the impact with the water in the bottom.