xp-100 7mm br

[DavidFagan]

I didn't think there was a "min or max" COAL unless the bullet wasn't at least seated 1/2 way into the neck to make sure it's squarely aligned or wouldn't fit into a magazine.
I believe the best answer is to partially size a case neck, seat, eject, measure (pull with a kinetic hammer) and repeat several times.
Epoxying a bullet in the neck and allowing it to dry is also another option.