First let me state I do not know the following for sure, but am guessing from what I do know ofthe Lee manual.
The Lee book is built on data from the various powder company load pamplets and old bullet manufactures data that they have released to Lee. The data isn`t bullet specific, that is it doesn`t list Bullet brand "X" as the bullet used in the data. They list a load as from "A" to "X" amount of powder with generic brand bullet of "Y" weight. The min/max COLs given are the I THINK shortest and longest COL found in the data they compiled from the multiple companies data used to arrive at the min/max powder charge and pressure values.
Once more! I may be wrong, this is just a guess.
I am quite sure though the data they use has been compiled from other multiple sources; IE: Hodgdon, Speer, Alliant, Ramshot, ect. None of it is from Lees own lab.