[Anton]

DRG,
you just posted a screenshot of the Game Guide fragment that I quoted in the opening post. What made you think I was unaware of it? On the contrary—I have read it and found it wrong, i.e. not reflecting the actual behavior of the game. I described an experiment that proves my statement. How would you interpret its outcome in terms of the quoted documentation for Delay?

It is the following comment by Imp that I suspected of being based on inside knowledge rather than on documentation, and still do:

Originally Posted by Imp

Every 0.1 reduces the number of shells fired that turn so from most to least shells fired.
0.0 - 0.1 - 0.2 - 0.3 - 0.4 - 0.5

You elaborate—

Originally Posted by DRG

As well the delay time is also tied to the experience and morale ( and health. ) of your gunners. A low exp and mor unit might have, for example a 5.2 delay but a unit with high exp and mor might be 3.5 AS WELL AS the observer unit that is calling the fire. An experienced FOO and gunners will work better and faster and more accurately than ones with less experience or who may have taken damage.

Thanks, but what are the exact dependencies? Without them one feels like groping in the dark. A more transparent explanation in the documentation and in the interface of what contributes to each specific delay value would make the game much more user-friendly. And now I am forced to discover the underlying algorithm by lots of testing, which is a long and tedious job.