i usually use kanthal and ss 316l 28g. im now enjoying contact coils. just started testing 30g ss, seems to be fine. 6 wraps, contact, 2.5mm id, firing at 8-10w.
30g is a bit flimsy. care in removing cotton is needed.
I wind my 28ga coils tightly on a rod with coil turns touching, then I stretch and re-compress the coils while they are still on the mandrel rod. When you do that you are left with a tiny gap between the coils. I like to think that the tiny space between the coils exposes the juice to more wire area. It's just enough spacing to see light between the coils. We all have our favorite coil building procedure.