I started at .020" for this trial. Used the OAL gage to find the lands by tapping on the end to seat the bullet just enough to hold it as the modified case was withdrawn, that length measured 3.345" counting the length of the comparator so I began at 3.325". No particular reason to start there except that was what Erik did in his video.

Gunnery, gunnery, gunnery.
Hit the target, all else is twaddle!