Forming .358 WSSM cases from .25 WSSM cases required me to learn about annealing. This is what I have learned so far:
- The brass should be heated until it starts to glow a dull red. In my experience, I need the room to be almost completely dark to see it. Not hot enough, and there is no effect. Too hot, and the brass is ruined.
- It is imperative that the head and most of the body do not get annealed. Those parts of the case must retain their hardness. A softened case head is dangerous to fire. This is easily prevented by placing the case in a shallow pan of water, mouth up.
- Unlike steel, quenching has almost no effect on brass. What effect it does have is to harden it slightly. The is the opposite of our purpose in annealing, so let it air cool. Standing in a pan of water, this won't take long.
- The case should be rotating so that it is heated evenly on all the way around. I found this out the hard way. Annealing .30 caliber brass, then expanding it to .35 caliber, the side with the darkest staining always ended up longer. I don't know if that was the softest side or the hardest side, but it is clear that the neck was not getting annealed uniformly all the way around.
So what am I going to do to anneal them evenly? Chuck them up in a drill? This leaves me open to more risk of overheating the case head. Maybe I need a lazy susan or some kind of rotating platform I can put a bowl of water on.