Pro-advice:
You can calculate future distance of target closing before you simply from head by its current distance and its current angle on bow
every 6 degrees of AoB until 30 degrees means current distance *0.1 if you want to fire on it at its 90 AoB (when its course will be perpendicular to bearing which you see it at).
So if its current distance is 5000m and its at 6 degrees AoB (close to directly against you) it will be 500m out of you at 90 AoB.
- 1000m if it has 12 AoB
- 1500m - 18AoB
- ... and so on
You can set distance to TDC in advance and leave it
If it has more than 30 AoB, its not by 0.1 every 6 degrees anymore, you has to look into sine tables
