Ammunition cartrige brass annealing

May 8, 2011Hello Everyone:

I'm not an engineer. But I am always interested in the #-Link-Snipped-# behind things. I'm an avid reloader of ammunition and work with brass cases alot. Today an issue came up where this person presented his friend's process for annealing brass:

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For those of you who don't enjoy this #-Link-Snipped-#, we anneal brass to remove the effects of work hardening to make it last longer. When a cartrige is fired, it expands to seal the firearm chamber. When we reload it, we squeeze the case back to size by running it through a series of dies. This work hardens the brass and it eventually splits. When we anneal the case, we heat the bullet end of an empty case untill it glows in hopes of softening it. We do not heat the whole case because we want the bottom of the case hard in odrer to preserve it's strength.

In the above thread, the gentleman heats the whole case until it glows, then quenches it in used motor oil. He does this twice. Being you are the masters of metal, could you explain what is happening to the brass?

Thanks,

-918v