300 WM Brass with circle on brass below shoulder- cause?

DIBBS

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  • Aug 21, 2008
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    While inspecting and sizing 2x fired Black Hills Match 300 WM Brass tonight, I discovered one case in the lot of brass to be sized, that had what appears to be a perfect circle just below the shoulder.

    It was shot in a Bighorn SR3, unknown weather conditions since I didn't see it till now. Would a speck of water cause this, or is it more likely a manufacturing defect that wasn't discovered till now. You can feel it with your fingernail. Thoughts?

    I only found one case in the lot of ~75 that I was processing that had this. I'll look at the remainder of loaded cases at the range tomorrow to see if any of them are similar.





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    I am not sure where I bought the brass, I bought it as once fired and have had it for ~ 15 years before putting it in service. I posted this on accurate shooter as well, and the consensus was that it was a pressure test barrel piston mark as well. Thanks.


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