Short necked, blown out .30-.338 Lapua. Very potent .30 cal. It'd be my pick of the .30 cals and what I had planned (essentially) to have made until I realized that, in general, for killing elk past 1K, a .338 Lap. Imp. would have substantially better terminal effects for a more sure kill.
Back in the early years of lrh.com, it was talked about quite a bit, but a quick search doesn't reveal much and I don't remember the case dimensions once formed. I know there are those on this board that do however, and perhaps they'll speak up here.