Bullet Comparator Question

[Dt219]

Here is how I find distance to the lands. The aggravating part is finding the right piece of brass. Find a piece of brass that’s been fired in that chamber that will hold a bullet, it doesn’t have to be tight, if you don’t have one you can use a Lee collet sizing die if you have one. Take that case swipe a little blue loctite inside the case neck, just start the bullet in the neck, then put the round in the chamber and let the bolt down easy, (might have to use forward assist ). Let it set 5 mins and pull it out. Measure how ever you wish, ( I do cartridge base to bullet ogive) That will give distance to lands with that particular bullet. I use the loctite to keep the bullet from being pulled out and staying stuck in the chamber when you extract. Works great for me