I do admit it has been a long time since I was an electronics
technician, but if I remember correctly we never used standard AWG wire for kilovolt work. I did a small stint building high voltage power supplies in the early 70s and the wire on the high voltage side looked almost like a spark plug
wire. I believe that AWG wire insulation
is only rated for 600 volts. I seriously doubt that a chart for standard AWG wire guages is intended for KV use.
that I use for my wire sizing are the ones in the west marine
catalog which compare well, if not exactly with the Blueseas chart. On the other hand looking at the posted chart American Wire Gauge table and AWG Electrical Current Load Limits with skin depth frequencies and wire strength
there seems to be a disconnect. If you are to take the power transmission
rating one would expect that the voltage drop charts
would begin at that rating rather than the chassis rating. If one uses the calculator at the bottom of the chart, one sees that the chassis rating gives a 10% voltage drop at the chassis rating and a 3% at the power transmission rating for short runs (I used 10 feet one way) at 12V. It would seem that if I use a 3% drop chart I'm getting the proper results for the power transmission rating. Indeed 8 guage is about right for an incandescent bulb up a 60 ft mast
bundled with other wires.