Re: New Brass, .243 Cracked neck
The annealing temperature for cartridge brass is about 650 degrees F. Brass conducts heat pretty fast and if you tried to get the shoulder that hot then the head of the case would approach that too. There is a very narrow temperature range that you want for annealing. Too cold and it won't anneal and too hot and the crystalline state of the brass completely changes and becomes unusable for cartridges. Firing the cases in a gun never gets the brass that hot. That hot, the brass case would glow like red hot steel (some other color though).
The common way cartridge cases are annealed is to fill a shallow dish with water and stand the case in the water. The level should be well above the head of case, perhaps 1/2 inch to 3/4 inch deep. You then heat the shoulder and neck area to the desired temperature and tip it into the water so that the whole of the case is submerged.
I think the operation too tricky for me as it is too easy to ruin the cases and not know it, leading to a possible case split during firing, releasing up to 60,000 psi of gases into the chamber and perhaps onto me. It is not worth it to me.