Thanks very much for the comments. As I am new to reloading, I have been struggling with the issue of OAL and all the things you mentioned in your post. Your point is well taken, the differences can be measured but it depends upon how you hold the calibers, the brand of brass, the variance in the press, the dies etc. Controlling the exact actual difference is elusive.
The other element here is comprehending the actual length. I cannot visually see a 0.005 or even a 0.10 difference in bullet length which leaves one only with the numbers on the digital caliber to rely upon.
