measuring from the point of the bullet is not a terribly accurate method and basic saami spec is not good enough. you need to use the max coal from the load manual for the specific bullet in question.
reason being is the widest furthest forward point of the bullet. the bullet maker takes the difference between the ogive and the bullet tip into consideration when listing a max oal.
to find your rifle's true allowable max oal you need a bullet comparator modified case and calipers.
trying to determine coal with tape sharpies and measuring sticks is going to cause a kaboom at some point.
get the proper tools to do it correctly and safely.