[kosciusko51]

You might like this link:

http://mathscinotes.com/2017/12/earths-curvature-and-battleship-gunnery/

Similar idea, but put into practical use.

[philman_36]

Here's a better one for you...
The Navy Wants To Fire Its Ridiculously Strong Railgun From The Ocean
How far the shot goes depends on the power supplied. Smaller railguns might release a projectile at 20 megajoules, which means that at flying level it can go up to 60 miles. A larger railgun, the kind that draws 25 megawatts of power, can release projectiles at 32 megajoules of energy, where they will travel up to a 110 miles at a level trajectory.

Think about that! Why would the Navy invest in a device that fires on a "level" (or FLAT) trajectory on a supposedly curved surface?