OAL off the throat... I know, I know...
There seem to be several recommendations about setting bullet OAL off the lands and grooves. Most say anywhere from .002" - .010" somewhere, closer being "more ideal".
There's a fairly well known riflesmith who says anything between .005 - .050" will do (point oh five oh). He says the distance of the 'jump' from the casing to the throat isn't very important--all that really matters is that the bullet's axis doesn't waver from its' "concentricity" as it goes from casing to bore. That is to say, so long as the OAL allows the bullet to contact the bore while still truly aligned in the casing as it was reloaded, the 'at rest' distance (OAL) off the lands and grooves doesn't matter. Then again, he's not (and never has been, to my knowledge) a competitor. But his rifles shoot like lasers.
What do ya'll think?