This brass is from a custom build of a friends. I have never seen (Winchester) brass do this, it was brand new never fired, FL sized before loaded. The same lot of brass is used in his other 22-250 rifles for multiple firings. I am questioning if the neck angle in the chamber is a few thou off. Not every piece does this, maybe 50% of the time. I notice a sharp/shiny ring at the neck shoulder junction. Mechanically it looks like the brass is being chambered hard at that point before it's shot. I would think it's causing a crimp point creating the failure.
He has a Redding FL die and neck sizer. He has also taken about thou off the shell holder, I will check in to get more details this week and see if an expander ball has been used.
He has a Redding FL die and neck sizer. He has also taken about thou off the shell holder, I will check in to get more details this week and see if an expander ball has been used.



