I used to have fits with concentricity issues, using expanders, and even bushing sizers. I found simplification by just by buying RCBS's tube Rifle bullet feeders for both .223 and .308 which come with "M" style neck expander dies too.......then I could use a regular RCBS sizer with the expander rod removed in station 1 and the "M" neck expander in 2 (priming in the up stroke), then simply charging in 3, powder checking in 4, bullet feeder in 5, seat in 6, and taper crimp in 7.......in both calibers, but that requires 7 or more stations.........or six on my Lee 6000 using my ...feed N seat coupler on that press........but you could use a Noe "M" expander too on a single stage in batch mode. I personally much prefer "M' expanders over bushing dies or conventional sizers with expander rods. That's my admittedly very divergent view.
I've learned to hate expander buttons that deform stretch and ruin accuracy.