Vertical Split in case body when fireforming

Exact Middle of the crack, on new and cracked brass. Just wondering on the difference. New vs fired.
Wouldn't it be larger because it has split?
I guess what I'm saying is it will be larger because it opened up.
however, I think you're onto something and he should measure all of his brass in that area to get an idea. too bad you can't get a ball mic down in there and measure the middle of the Brass case.

I know you probably will have to send those off to Lapua, but I would try to cut one lengthwise in half to see if it is thin in that area. Also, after you do that, maybe you can find someone to do a Rockwell hardness test.
 
Exact Middle of the crack, on new and cracked brass. Just wondering on the difference. New vs fired.

I'll see if I can devise a method to accurately measure there. I only have a pair of calipers, so we'll see what I can come up with
 
Wouldn't it be larger because it has split?
Brass would expand to the chamber, if the pressure was high enough. Then spring back. For the most part, brass cant be larger, in diameter, then the chamber.
Should not be any chamber damage from the gas escaping.

In some handguns, S&W M19, a maximum + load will expand the cylinder. Pushed by the brass. The cylinder will return to its orginal size, making the brass stick in the chamber, on extraction. Around .0005" very small amount.
 
I'll see if I can devise a method to accurately measure there. I only have a pair of calipers, so we'll see what I can come up with
Cut the shoulder/body junction..get measurement..the cut further back and get measurement....
Or...
Cut the body loose from the base and body/shoulder area and test it flattened
 
The RCBS concentricity gauge has a device for measuring brass thickness in the head section to see if a separation would come about. This should be helpful in getting this measurement. The long rod with the pointed tip is what is used. Might be able to get an idea using this.
rc_87310-casemastergaugingtool.jpg
JMO
 
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