Chance of gun loss

[krmiller]

Any knowledge on how artillery gun loss is calculated in counter battery fire versus just fatigue increase?

Is it more advantageous to fire all guns in a hex at once or to fire one unit after the other in counter battery fire?

If the calculation just sums up the propability to loose a single gun if all are fired at once, it is better to fire them unit by unit to propably destroy more than one gun.

In answer to your questions, from Combat Results section of User Help.

Artillery gun losses resulting from enemy artillery are calculated on the basis of 1 gun = 25 men. Combat losses from artillery fire of less than 25 men result in a probability of a 1-gun loss proportional to the value. Thus, a combat loss of 5 men applied to an artillery unit would result in a probability of 5/25 = 20% that a one gun loss would occur.

This is not documented but I have been told
Firing multiple units at once does not increase the effectiveness of fire. Each unit's fire result is handled separately then the total casualties and fatigue are added together and the losses displayed. However, there are some advantages to firing stacked units.

This is also something I have learned.
    Firing stacked units does result in all the casualties being added together before checks are made for whether or not a unit will check morale and whether or not guns are destroyed or crews are killed.