Annealing is to remove all hardness, like the stress release I posted about above. What you mean is to temper or draw back some of the hardness in the receiver, and that works fine for the russians because differential heat treating would be a pain in the a$$ in a production setting but it is not better. Even if you just harden the axis holes you should still temper them. There is plenty of good info on the web for heat treating and tempering.3/325 said:The Russians heat treated the entire receiver. To keep it from being to brittle you have to aneal it, heat it at a low temp for a short period of time. If you aneal it correctly it will retain most of it's "hardness" but not be as brittle.