So, fairly new to this, but I managed to find what I think is a bug / undocumented feature in the BIS_ARTY_F_ExecuteTemplateMission function.
It seems if you synchronize a Podnos 2B14 mortar (possibly others as well) to an artillery logic, and then call BIS_ARTY_F_ExecuteTemplateMission using that logic, the mortar's range is permanently changed to close to x10 the normal range brackets, meaning the mortar can (if the AI gunner is killed and you take over) shoot 40000m with it according to the artillery computer.
I was able to have this happen reliably once the function is called using the following code.
_startHE_template = ["IMMEDIATE", "HE", 2, 8];
_targetPos = getPosASL mortar_target;
[mortar_logic, _targetPos, _startHE_template] call BIS_ARTY_F_ExecuteTemplateMission;
Is this known and is there any way around this? Ostensibly, in the mission I am making, the player might get a hold of and use the mortar after it has fired a few times.