While firing organ guns, instead of firing all of the bullets in a single burst, it fires each shot one at a time.
Here’s how to reproduce the problem:
It should be tested, how much difference in effectiveness will it exactly cause
Basically, instead of doing its 20 damage (20 damage from the base bullet and 4-8 damage, depending on if the bullet hits a different target, from 4 secondary bullets) and initiating the 3.45 second reload time (on 1.0 speed), it fires anywhere from 3-4 volleys, which takes about 2 seconds to finish its volleys, adds up to about 5.45 seconds before it can fire its primary damage-dealing bullet, thus reducing its overall damage per second.
This also means that it is difficult to fire, move, and fire again with organ guns (similar to the way archers fire, then walk away, and instantly fire again after their reload time has run out).
Another important issue this causes is that once the target the organ gun is focused on dies, it stops firing new volleys, meaning if multiple organ guns target the same unit, the unit will die fairly quickly and their other bullets will never be shot. This causes the organ gun to miss out on a lot of extra damage to units around it. To only way to really avoid this to to have each individual organ gun target a different unit so that each bullet can be fired from ever gun instead of stopping because the current target is dead, though this way is inefficient and takes too much time to set different targets for each unit.