I had myself in the same bind. I have about 1500 piece of 6BR brass because i found with working so much, the necks became stiff.
I tried different methods from tryuing the torch/pan, lead dip, I even built my own machine with a barbeque motor and a 12" saw blade.
I was so afraid a screwing things up, but came to realize I had nothing to lose. Here is what I have discovered and i now have all rehabilitated brass!!:
You do not need to rotate the cases in the flame
I set my cases up on a glass-top patio table, I use a standard propane torch with a 1" inner blue flame. I tend to do this in the evening as the sun is down,,,
I hold the torch so that the inner blue flame is 1/4" from the neck and the outer flame completely envelops the neck.
In roughly 13 seconds, you will see the flame beyond the neck change color to pink, and you will see a patina on the case shoulder that looks exactly like a brand new Lapua case.
I let them air cool
Good as new.
That simple.
