Best way to describe it.
Effects of COAL and CBTO | Part 2 | Berger Bullets Blog
The red thing on the caliber is how you measure the bullet ogive.
If you are compressing your loads to get the AOL, and deforming the bullet tip. You GOT PROBLEMS! I would switch to a faster burning powder that took less to get the velocity you want. Are you using bullets with a cannelure or smooth sided? Also, I gave up on compressed loads. Not worth the trouble. Especially if you are shooting with a semi-auto. Alot of times, the bullet will move out of the case with it being slammed into position by the bolt.
Long time ago. I ran into the same problem you have now with AOL. Found out if I sort through the bullets and group them. I eliminated the problem.