I had a neck split so I heat softened my cases.. This caused some light neck tensions, and that was new but now already the ends of the case mouths are already hard after two fireings.. Its hot out, and im using hotter loads as this is where im getting some better groups.. Is this from something im doing wrong, the hot temps, hot charges, winchester cases, or a 6mm problem? thanks dave

Dave- sounds like a combination of a couple of things. Hot loads, your resizing die is "working" the brass too much, and possibly the brass.


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Lee's collet neck sizer will help to make your brass last longer. Heat softened? Is that another way to say anneal the case neck?