Final Defensive Fire question

[Barkhorn (OP)]

If I build a gauss cannon and corresponding fire control with a range of less than 10,000 km will I get to have a round of final defensive fire?  I know the minimum combat distance is 10k, but the wiki says FDF occurs during the move increment in which the missiles would intercept their target.  Which leads me to believe I might get a round of FDF regardless of how short-ranged my gauss cannon is.

So which is it?  Is 10k the minimum distance, or will you always get an FDF regardless of how short-ranged your guns are?

[83athom]

Yes you will get a shot. Final Defense fire is at a range of 1000km all the way to the ships hull.

[Father Tim]

Final Defensive Fire is calculated as if the range were 10,000 km, so if your guns are shorter-ranged than that their chance to hit will be zero.  Aurora will still perform the calculation and inform you that FDF occurred, but you won't shoot down any missiles.

[AL]

While we're here, I do have a question of my own:
In my recent campaign, I've been trying to attack an NPR homeworld but discovered the inevitable AAM spam that occurs whenever I try to close to weapon range (my empire doesn't have missile tech at this stage).   When my ships are retreating from the missiles, my point defense (set on final defensive fire) deals with the barrage flawlessly - but the problem comes when my ships are either stationary or advancing towards the planet.   Sometimes my point defense works as expected, but sometimes only one ship will attempt FDF (usually the one that was targeted).
The missiles were always detected with a fair margin before my fleet and the same issue occurred regardless of the increment length and whether my fleet was in a single task group or not.
I'm don't know what else could be relevant but I'm fairly sure this isn't supposed to happen anyway.  Opinions?