Interesting Robert- I've not seen one wiht a shorter than 8mm headspacing body/shoulder length.

Also interesting in the tight neck problem - could be extra thick brass? The only time I ran into this was when forming some 9l.3x57's using .30/06 brass.

I did find PriviPartisan 9.3x57 brass to have thicker neck walls than necked up 8x57 RP brass.