If somebody figures it out, please post here. I have xdies for 30'06 and haven't used the "xdie" portion of the die yet (I keep the mandrel backed out so it doesn't contact the brass mouth) so I just use them like regular dies. I think the key is to trim the bras .020" shorter than spec, then supposedly it works. The extra .020" probably makes up for the stretching the expander ball does. If you have a Lee trimmer, you can't trim brass any shorter than spec, so it's not exactly possible unless you grind off the guide-pin on the lee trimmer, i bought an extra trimmer, pin so maybe i'll do just that and give it a try.
Measuring every single piece of brass seriously sux. If the xdie prevents this, I could probably go full-progressive with rifle brass (using rcbs pro 2000 press).
--edfardos