They probably wouldn't be blowing up merchant vessels like U-Boats, but they certainly would still spend whatever money it takes though: Mark 48 torpedos are a cool $1M to $3.5M.
I think the main advantage for rail guns are that they allow a much higher volume of fire and faster time to engage more targets. It just happens to use cheaper ammo - I'm sure the gun will be much more expensive to make than a standard machined barrel.
They probably wouldn't be blowing up merchant vessels like U-Boats
But a part of the point is that they could in theory.
they certainly would still spend whatever money it takes though: Mark 48 torpedos are a cool $1M to $3.5M.
This would be dandy for blowing up a submarine or major warship which costs a lot more. This might also be viable for "demonstrating" your capabilities one or several times. Sinking a major merchant marine fleet this way wouldn't be cost effective.
It just happens to use cheaper ammo - I'm sure the gun will be much more expensive to make than a standard machined barrel.
With a 200 mile stand-off range, a much more expensive gun would still make sense. The extreme range would make such a weapon more survivable. There would also be applications for land to shore fire support.
http://en.wikipedia.org/wiki/Mark_48_torpedo
I think the main advantage for rail guns are that they allow a much higher volume of fire and faster time to engage more targets. It just happens to use cheaper ammo - I'm sure the gun will be much more expensive to make than a standard machined barrel.