That makes sense for your application. I would still do the X62 and just load down a bit, but X57 brass is so available (as in size up 8X57) and cheap, your way definitely has advantages.
I totally agree that the x62 would be the better route for this, in fact I have already dies and 200pcs new brass here for the x62.
Funny about the 9.3x57. While it's very similar to the 358Winchester, it gets no respect at all but at the same time everyone thinks the 358 is kickin'.
