i have used the seating method you use for years but I put a little glue in the neck and chamber the round and let set when glue sets up you have a consistent measurement because it can’t move. DavidI use an unprimed dummy case sized and given a minimum amount of neck tension. I seat the bullet long and ease it into the chamber. Generally it extracts without sticking in the lands. I now have a dummy round seated to touch. I've been using micrometer controlled seating dies or Redding competition seat dies. Use the dummy round to set the seater die to touch and then test fire a few. Very easy to screw the seater plug down by any amount that you want to. With the dummy you can always return the seat die to the touch position if you lost or forgot to write down the micrometer reading. Range pick up brass is good for this. I make a seater dummy for each type of bullet I use. Of course any loaded round must fit in the magazine.