[Unclenick]

I think Lee's minimum COL is an attempt to make up for being unspecific about the bullet beyond its weight and construction type. For example, in the .308 you could observe his minimum length while loading the Hornady 150 grain SST to its crimp cannelure (2.735" COL), but could not do so with the Hornady 150 grain round nose, whose cannelure is located to get 2.520" COL.

In other words, Lee is indirectly saying his load data would not be valid for that round nose bullet seated as designed. You would need to reduce his charges for it.

By contrast, the bullet maker manuals normally list separate COL's for each bullet of a given weight that they make. The drawback is they also only list one range of powder charges for all that must be safe at the starting end for the deepest seating bullet in the group, shortchanging the performance of the ones that seat further out.

Some days there is just no free lunch.