If you use a candle flame to
lightly put smoke marks on the neck & shoulder of the case it's much easier to see the die working down the neck BTW (This used to be known as "smudging a case").
It gives the advantage of being able to BOTH neck size & full length resize with the same die as you'll eventually need to do a full length resize as the case will swell a tad every time & will get tight to chamber. When this happens just set the die to F/L resize, resize & back off again for more neck sizing.