PreSeating Tool ?

[Rocky Raab]

Ol Joe's way is simply the "outside" method doing what I described as the "inside" way.
They'll both work fine, but sometimes the die is too tall/long for a standard caliper to span usng the outside method (As I learned once). If so, measure using the "inside" method and record that number for future use.

You only need to do the extra steps of measuring the gap between the die and shellholder plus the shellholder step if you are trying to pre-compute a seating depth. If you already have that and are merely trying to return to a setting, either the inside or outside measurement will work fine.

An even simpler way is to make up a dummy cartridge (no primer or powder) with that type bullet and keep it as a reference. Just slowly adjust the die down until it and the seater stem just touch the dummy, and you're set again.