My method is pretty easy. I take a resized case with no primer in it, run the neck of the case over the expanded plug a half dozen times. Then partially seat a bullet. Then I chamber that round. BY running the neck over the expanded plug several times, the bullet is a snuff fir in the neck, but loose enough so that when it is chambered, the rifling will push the bullet back down into the case instead of the bullet becoming lodged in the lands. Then, check to see if that cartridge length will function through the action. If it will function, that is your COAL touching lands, and you can measure it, and then adjust to what ever distance you want to be off the lands. Of course, if it doesn't function through the magazine and/or eject properly, you COAL will have to be adjusted to that consideration.
