I have zero sources of information but would be willing to bet the tolerances on these bullets are larger than the 6/10,000 th's your claiming to be the difference.
Thickness of a human hair is ~ 4/1000 th's. So your claiming 6/10,000 is the difference - an order of magnitude smaller than the thickness of a human hair. Wonder what the tolerance is on the machining? And this was in what year?
