Yeah that's one of the ones I was referring to earlier The nice thing about that one is that he was able to adapt existing dies (I think it was 35 Rem dies) so taht it is basically a .35 Remington "short". A few more listed here at the bottom of the page:
I ordered a .35x39 reamer and it opens the neck up such that it basically makes a straight-wall rimless cartridge out of a 7.62x39 case. That's on one of my other old threads - probably around 2006 or so. Wasn't too impressed.