new case annealer

[semtav]

I did some testing on if tumbling hardens the brass. this is what I did.
I had some once fired brass that I got at a gun show or some place, it has a head stamp of pmc, I made a steel shaft that would fit snug inside the cases. using my Lee lead hardness tester, I used two cases to test, both cases had a dimple size of .024. after annealing the dimple size was .030. today I tumbled them with other cases for two hours, I use half ss pins and half ceramic, the dimple size after tumbling was .026, so in this test they did get harder, now I know its a matter how you read the scale in the magnifier but I was careful in reading it and both cases read the same.
Two things surprised me though, after tumbling,the steel shaft was hard to get in the cases basically had to resize, the other thing was how nicked up the cases were when looking through the magnifier.
If someone has a better way to test this I would be interested in your results.

Thanks Dave. Kinda wondered about that. Be interesting to see what it reads now after you shoot it once.

The reasons the steel shaft was hard to insert after tumbling is due to peening of the case lips which results in reducing the ID of the case lip.

Wayne

I don't remember having that problem with the old green RCBS vibratory cleaner.
But I've tried every way recommended on here to not get peened mouths with the thumblers tumbler and always did so I just quit tumbling altogether and no more peened mouths !!

[Shadow 4]

I did some testing on if tumbling hardens the brass. this is what I did.
I had some once fired brass that I got at a gun show or some place, it has a head stamp of pmc, I made a steel shaft that would fit snug inside the cases. using my Lee lead hardness tester, I used two cases to test, both cases had a dimple size of .024. after annealing the dimple size was .030. today I tumbled them with other cases for two hours, I use half ss pins and half ceramic, the dimple size after tumbling was .026, so in this test they did get harder, now I know its a matter how you read the scale in the magnifier but I was careful in reading it and both cases read the same.
Two things surprised me though, after tumbling,the steel shaft was hard to get in the cases basically had to resize, the other thing was how nicked up the cases were when looking through the magnifier.
If someone has a better way to test this I would be interested in your results.

I do, quit tumbling after annealing, corn cob media in a vibratory after annealing doesn't do that.
Pretty simple

[TexasMac]

The reasons the steel shaft was hard to insert after tumbling is due to peening of the case lips which results in reducing the ID of the case lip.
Wayne

I don't remember having that problem with the old green RCBS vibratory cleaner.
But I've tried every way recommended on here to not get peened mouths with the thumblers tumbler and always did so I just quit tumbling altogether and no more peened mouths !!

I agree. The following comments are from an article I posted on my website.

"Due to additional testing there’s no question in my mind that peening is definitely due to rotary tumbling, and the rate of peening is determined by several factors. If someone tumbling brass with ceramic or stainless media does not believe peening is taking place than they have not measured the lip width close enough before and after removing the brass from the tumble. I have proven to myself beyond a shadow of doubt that I can control the rate of peening but it is inescapable, i.e., peening cannot be completely eliminated when using a rotating tumbler. The only methods I know of to eliminate peening is to use an ultrasonic cleaner or a vibrating-style tumbler."

For more details on my peening experimenting click on the link below and page down to the section titled Case Lip Peening.
http://www.texas-mac.com/Case_Cleaning_ ... _Pins.html

Wayne