Brass spring back??

[Uncle Ed]

If you pause for a few seconds at the top of the ram stroke and keep the case inside the die this reduces brass spring back.

As another example for semi-autos is the full length resized case diameter should be .003 to .005 smaller than its fired diameter. This allows the case body to spring back from the chamber walls and extract reliably. As another example for semi-autos is the full length resized and case diameter should be .003 to .005 smaller than its fired diameter. This allows the case body to spring back from the chamber walls and extract reliably.

 

[mikecr]

After brass has work hardened does it have more spring back or less?

Spring back displacement remains pretty much the same, but deformation (yielding) offsets where the case springs back to. That is, if normal springback is 0.0005 (it's elastic region), and you size beyond that to cause yielding, it still springs back 0.0005, but to a new offset dimension.
What changes with work hardening is springback FORCE. That is, the tension needed to cause yielding is higher in work hardened brass, and lower in freshly annealed brass.
An adjustment to this normal, is with over annealing. If you full anneal, you will kill brass, in that you will remove nearly all springback. It would have to be work hardened back to normal to recover.

So here, please describe your sizing.
Are you expanding necks?