So here's something I haven't seen in the past. While resizing 40 brass mixed head stamp I have ran across 12 in 3000 cases that are huge all the way up the case. I know a couple cases are CBC brass. Unsized normal brass. Big brass. Bulge is all the way around the case and a lot further up then the dreaded Glock bulge isn't it. I started it into the sizer die a little before realizing there was a problem. Here are a couple that weren't as bulged and made it further into the sizer. So what causes this?