Sometimes you see something that just amazes you, and you have to share. A friend of mine in North Texas is an amazing engineer, and he developed an auto annealer for .223 brass:
Okay guys, I've been shooting for years, and never heard of an annealer for brass. I'm assuming it has something to do with reloading, since I know very little about that (just bought a press, need to get my bench built so I can learn to use it.) I do know metal working, and annealing, from my understanding, has to do with heating a metal and allowing it to cool slowly, effectively removing the hardening. Like a high carbon steel knife is hardened by heating, then cooling it rapidly, if you heat it again, and allow it to cool slowly, the hardening process is effectively reversed. Okay, I get off topic a lot, but anyway, WHY do you need to anneal your brass? Is it required for reloading? Does it just simplify the process? Wouldn't rehardening be needed? I'm lost.
The short version: When you fire a round it stretches the brass to chamber dimensions. When you size it is compresses it back to smaller dimensions. This work hardens the brass. Eventually the brass will crack/split, and the case is ruined.
This annealing (or stress relieving, depending on how hot you get it) reduces or removes the effect of work hardening, allowing many more loadings on the same piece of brass. Properly done it will virtually eliminate neck splits.
It is very hard to do with the relatively short pistol brass, as you must not anneal the case head/web area or risk head separations. With rifle brass, especially with neck or partial full length sizing, the shoulder to neck area is by far the most worked (and therefore hardened) area. It is also the easiest to anneal without affecting the critical web and head areas.
Thanks guys, that makes sense now. Hmmm.....guess I'll be buying me one of them anealers at some point, but me thinks I don't need one just yet. Better to learn what the heck I'm doing first, might not be bad to see a few bad cases so I know what I'm looking for before I start trying to extend their lives huh?