I was hoping Dave Patterson would have something to share for all here to learn from including myself.

JLouis

In my bullet and chamber designs I've used 0.200" of freebore to help align a close-fitting bullet to this freebore area. I cam the bullet into the forcing cone when I raise the block to where I see about 0.040" swage on the front driving band of the bullet (not tapered). I also have a loose fit of the bullet in the case as I do not want the case to influence the bullet's alignment to the bore. I also, when cutting the chamber, get the the section of the bore where the bullet's shank would sit in the chamber, to run absolutely concentric to the lathe before reaming the chamber.

I get good accuracy with these specifics. I posted a pic of my results at 300 meters under the Barrel Blanks topic. This is not the only way to achieve good accuracy, but the one I've used.