Well I annealed some cases today.
I used a small camping propane bottle with a 90deg shaft torch.
Its for mapp but worked great.
Bottle is pretty stable and you can use a propane base if you wanted.
Went well. I wore a head lamp and could see the tempilac very clearly.
It was very obvious when it changed.
I used my 12v Bosch drill.
I could still see the tempilac at decent rotation but settled for a manageable speed.
I held the brass about .75" away from the torch mouth.
I counted off 1 mississippi, 2 mississippi, etc to gauge approximately how long it takes.
Pretty much the tempilac changed right as I said 4.
So,
1 mississippi
2 mississippi
3 mississippi
4.
Of course I used tempilac on every case.
I also painted a line of tempilac on the outside of a piece of brass from neck to base to see how hot the lower part got.
The tempilac really only changed where it was in the flame.