Bullets fired at any verticle angle will fall 'ballistically' which is a fore-shortened sort-of-parabolic curve due to air friction. If the angle is large, then the fall is essentially at terminal velocity. A shot at a drone is likely to be at a large angle.

The reports of 'celebratory gunfire' deaths are all necessarily speculative - the angle of the shot is impossible to measure. We can resort to physics to get a better answer than that derived from headlines.