Different bullets have different lengths to the full diameter, ie: ogive of the bullet.

You will know you are sizing at the correct height when you size the neck almost to the base, at the shoulder, but do NO touch the shoulder. That is a good place to stop, so you do NOT push the shoulder back.

Always start at the starting load in a manual. Not really knowing what you are doing with the sizing and starting at a max. load is a quick way to more trouble than you need at this point.