dixieppc said:
[CatShooter's example Photo]
CatShooter
As per your image reposted above, I would have thrown the case on the left away because of not having hard data (hardness test results). I do use Tempilaq but only on the first few cases to get my timing down and then just let the machine (Giraud) do its thing from there. So if a case out of the batch turned up looking like the one on the left in your above example, it would get tossed. Luckily that hasn't happened yet.
Being new to annealing I am just wondering why the case on the left in your example did what it did barring that the flame heat and timing was the same for all cases and all cases were from the same lot.
I have to agree with your statement: "Annealing is part science and part black magic".
Best Regards.....
Dixieppc...
I wish I knew for sure. I have had this happen with two calibres - these (which are R-P .221 FurBalls), and Lapua 6mmBRs.
So, it happened to cases at opposite ends of the quality spectrum, and they do not use the same alloys (% of zinc wise), so it is not alloy related.
I do know this - in both times, some of the cases were polished and washed before annealing, and some of the cases were annealed out of the box.
These were two times that I found myself in the middle of bunches where I bought more (or neck turned more new cases) after I had been shooting some of them.... and I decided to bring all of the cases to the same place (neck hardness wise), so I did them all at once so I could start from "0", cuz I was changing some other things and didn't want to have to worry were the cases were, neck wise.
I don't know which, cuz I was not paying attention to that factor at the time.
The first time was with the Lapua 6mmBRs. I was doing a ton of them, (OK, not a ton, but over 1,000), so I was whipping through the lot. I noticed them as I was working along, and assumed that I did something wrong, like hold the case so the flame went down along the body and into the case holder thingie - and so I threw them away
The second time was with the .221 FurBalls, and I was paying better attention.
Now, here's the weird part (Na na na na Na na na na)... the weird ones annealed normally in the case holder - the color line ended just below the shoulder like the rest of them, and when I dropped them on to the foil, they would sit there for a second, and then this blue/magenta color would start running up the case like a fast growing fungus - it would take about two or three seconds to go from the blue colored line at the shoulder to the head. When I saw this, I knew I needed to take pictures and make case hardness measurements... which were even more surprising
Now, I know this much - there was no additional heat coming from anywhere - I drop hot cases on aluminum foil, which draws heat out, so cooling is faster.
If it was due to the way I do it, then there would be a lot of them, but only ~6 of the over 1,000 Lapua cases did this... and about 30 or the more than 500 .221 FurBall cases did it. And it only happened these two times, and I have been annealing the same way for many many years.
I think it has something to do with the washing and/or polishing, cuz I have never had anything like this when I annealed straight factory cases, either new or fired.
I now keep notes on where I am in the total process when annealing, but it has not happened again since the .221 FurBall pictures.
Next time I get a batch of new cases, I might break them up and see if I can reproduce this...
I will say this about annealed cases, if the
heads change color, and you don't know why, and can't measure them, then toss them, cyz it is not worth the risk of shooting a dead soft case head.