Reloading Suggestions?

This example is false, the neck is NOT pulled through by the expander, the brass that has been squeezed closely back to normal spec has only ONE place to go….the shoulder and neck, squeezing the neck smaller elongates it, just like fire forming an improved case shortens the neck, the brass has to migrate.
Hone your dies neck and polish the expander so that brass is only moved a total of .0015-.002” and the migration becomes a lot less. In fact any elongation after a couple of firings ceases to exist.

I disagree. But I think its semantics. The expander ball can and will pull the SHOULDER out, especially in cheap dies that have over resized the neck, or in brass that is hardened and has not been annealed, or has too little neck lube.

I am CERTAIN that sometimes the shoulder can get pulled back out by the expander. I measured cases identically resized, expanded with the ball, versus not and the ball expanded cases were showing a longer shoulder. Taught me the value of mandrels and annealing.....