Three more questions:
Bullet weight. If you are near the maximum for the bullet/powder combination, strange velocities can creep in as the powder burn gets erratic (spikey). This could be a danger sign. Not necessarily, but maybe.
Are the primer flash holes uniform?
Seating depth (as measured from the base of the bullet to the case web). I know, once the cartridge is assembled this cannot be measured directly, so we use the cartridge overall length. But if there is variation in the nose shape you can get some uncontrolled variation.
I love a puzzle.