posts under different threads:
1) Atmospheric friction at low altitudes is a problem. Even if ceramics and ablative coatings can deal with the heat, they may not deal
with the shock acceleration.
2) Rail guns are just ballistic guns and not scifi wunderwaffen. So attacks on cruise missiles and similar is not any sort of
superiority aspect of these weapons. Small missile interceptors are more effective since they are not limited by any line
3) They consume vast amounts of energy. Even though the US routinely propagandizes their development and planned
deployment on ships, this remains always in the future after years of hype. And installing them on ships is actually
practical with the right sort of power plant. Using rail guns to take out cruise missiles in the mountains on some truck
is dreaming in technicolor.
It appears that rail guns are more useful in orbit outside the atmosphere, but there you have the problem of power supply.
So they are a scifi spaceship weapon with limited utility in any real world situation for the foreseeable future.