Videos above show the old tried & true ways to make ammo,
Not many of us have 100,000 to 300,000 pound cast iron frame equipment anymore, or can dedicate an entire building to ONE machine.
Just for the record, your 'Accuracy' ammo isn't made that way, it's CNC collet rotary machines that have the capability to gauge/process each case individually.
You will see a couple of production electrical annealers, much more precise than flame annealing...
https://www.youtube.com/watch?v=LYk3_IcB4JI
https://www.youtube.com/watch?v=Ira3dmlclQ4
Home annealing unit, ready to run when you get it, no overheated cases.
https://www.youtube.com/watch?v=EGfGV8xrfak
This guy in particular goes into brass formula by manufacture, even if you gas anneal, this should give you something to think about.
https://www.youtube.com/watch?v=Zu9rva9uG6Y
If you SEE a color change, not a finish change, but the metal 'Glowing', you went WAY too far!
if you see a 'Puff' of smoke from the case, either the case wasn't cleaned correctly, and you just baked crud into the brass,
OR,
More likely with a torch, you just cooked trace minerals out of the case, soon to be followed by separating metals in the brass mix.