I have never measured bullet jump but I do like to be back just off the lands. I load the first bullet long to hit the lands and then seat a bit deeper each time till I can no longer feel the bullet touching the lands when closing the bolt and can no longer see the land marks on the bullet. In my rifles I can actually close the bolt and not feel the lands but still see very small marks where the bullet touched them. My opinion about the bullet jump is it is only worthwhile for competitive shooter's.
