Malm:
I have throated a few rifles that were chambered without a throat on the reamer. I could not find any information on how to determine proper throat length. Some sources said to throat for the bullet you are going to use, but did not offer any advice on how to throat for any particular bullet.
Seat the bullet so that the base of the bullet ends where you want it in the neck. Then, throat the barrel until the bullet in your 'dummy' case just contacts the lands.
Good shootin'. -Al
