50 if it hits the center subcell twice. I originally thought they caused twice as much damage because I was only meausuring one subcell.

The center cell is indeed hit twice, but the four corner cells aren't hit, which makes the total damage per shot 46 x 4000 = 184,000.

For launchers it works exactly the same way, so their max. damage per shot is 46 x 250000 = 11,500,000.