It's not meant for chasing the Lands. This tool properly used is for getting your seating depth and working up you load on a new rifle. After that you don't use it again unless you want to see how much it has eroded. You can measure and know exactly where the bullet is in relationship to lands/groves. After much shooting the distance with the bullet to L/G will increase due to erosion and there is no need to chase that.i dont really see a point with these tools ..following erosion maybe .. once you have a full head spaced shouldered peice of brass that is sized to match your chamber. make a dummy with it and keep seating deeper till you bolt closes like ya did to find the max 0 bumped crush fit shoulder
ydanroh tricks
The method you are mentioning has been used for as long as I can remember and before any type of measuring tools were made. It's a tried and trued method, but you have to know what you are doing. The issue with this method is that if you don't know what you are doing you could be jamming bullets too far into the lands and then cause overpressure.
Thanks