I'm as fond of long range bombardment as the next guy, but without a range calculating sight I think it would be a waste. Really what you are looking for is indirect fire, and the gunsight options in this game really do not support it. I would rather they work on the naval gunfire (giving us range calculation and better correction capability) first.
Using the main ".target xxx" command where the "xxx" is the range for the target to be placed,
there are also other modifiers which were unknown to me prior to hooking up with The 49ers
one evening for an indirect fire mission using a "battery" of about a half dozen M3s with the 75mm gun.
The two other modifiers are for elevation and traverse.
Basically, the command would look something like this: .target xxx yyy zzz
One guy is tasked to be the FO. He sets up within visual range of the field/base/town/strat to be hit.
The M3s deploy with all halftracks set up in line abreast formation; aligned with the "main"
gunner who works with the spotter who calls the fall of shot.
The main gunner uses as his initial reference point, the very bottom ring of the
target.
After a number of ranging shells are fired and the sweet spot found, the entire battery
opens fire using the then-determined parameters in the "target command".
Several batteries can be used, but obviously, depending on their placement, their
target commands would be different.
This method works great but is quite tedious and there's no visual or aural reward
for the gunners themselves who are unable to see or hear the rounds impact.