I have some South African PMP cases. They have a smaller capacity than all the others I have measured. So perhaps the web area is thicker and stronger. I used them in my short barrelled pig gun because of the smaller case capacity.
I made a few neck sizers and expanders for minimum sizing to get the ID I need. Ideally, there should be no expanding required but my sizer is for jacketed's and it works just fine for that purpose. For paper patching or cast I expand to the size required and it basically stays there.