Winter here and cold outside. Too much time on my hands.
Anyway, I was curious about the chamber on my 223 and measured several pieces of fired and unfired for two different factory brands. Checked the case length on 10 of each for a good average. Brand x averaged 1.756 unfired and 1.759 fired for a .003 stretch. Brand y averaged 1.741 unfired and 1.746 fired. I have no way to measure shoulder expansion, if that makes any difference. I put a piece of masking tape(~.004) on a couple of the spent cases and the bolt handle closed, but I could tell it was tight. Definitely smeared the tape some.

Doers this tell me anything at all regarding chamber tightness or sloppiness, or is it meaningless info?
And I already know I am ocd.