i meant a gun with a range huge enough that you could fire at things from out of range of the coastal guns, therefore a long gun
who knows these things
This is just whatever knowledge I have gathered, basically the range is dependant on the projectile's force when leaving the gun. And the projectile's area seen from the front + how well it is formed, as those two influence the air resistance.
Now, to get a projectile to be quick, you can do two things: Increase the percentage of gunpowder compared to the projectile (more energy by explosion acting on a smaller mass --> more speed), or increase the length of the barrel (because a certain percentage of the energy escapes). The latter seems to be about proportional to 1-SQRT(ratio bullet length to barrel length), meaning that, for example, the difference between a L/4 and a L/50 barrel seem to be about 30%. And yes, that is a very rough estimate, and does not include things like accuracy.
So, basically, the difference between a 'mortar' and a 'normal' artillery piece is that the former uses the fact that he has a very short barrel length to achieve a much higher calibre. Since a higher calibre means more explosives to fit in a high explosive shell, that also means more damage.
I also put it under a med/small slot as well Evil
EDIT: It's a turbine, not a boiler.
Well you need both turbines and boilers to make steam ship. In addition I'm not a big fan of designating variants with different names.
Call it the Annihilator B?