Agree, except you probably aren't gong to find calipers that are .0005 accurate. Calipers I don't trust just thousandths.
I think if a more people looked at reloading as a trial and error process, other than some scientific adventure, they would have an easier time with it. People spend all this time looking for the "perfect" OAL, the "perfect" powder charge, and perfect annealing. Then get shellacked by some shit pig who actually shoots, rather than spending all day raging about "best" reloading practices.
You change one variable, then test for probable improvement. Then you "test" some more [actually go shooting} to make sure that you can shoot the difference.