I full length size after annealing.

This puts some work hardening back into the brass. I think the step also makes the yield strength more consistent because strain hardening is fastest at the beginning and tapers off. That means that the spread of yield strengths is reduced.

The strain hardening curve might also explain why some folks report better accuracy with cases that have been fired one or more times. I report "some" folks because my shooting skills aren't in their ballpark!