__________________ “If ye love wealth better than liberty, the tranquility of servitude better than the animating contest of freedom, go home from us in peace. We ask not your counsels or arms. Crouch down and lick the hands which feed you. May your chains set lightly upon you, and may posterity forget that ye were our countrymen.” ― Samuel Adams
I believe the Springfield rifle issue is mostly about serial #s below 800,000. Early in the manufacture of the Springfields the arsenal switched from windows and natural light to electric lighting and that threw off the worker's sense of color so the rifle actions were being quenched at the wrong time. Quite a few were made and issued before a problem was noticed. Later on they developed high temp gauges and the problem went away.
As I understand it they had the gauges but as a typical gubmint worker is wont to do they took the easy way and tried to eyeball it, which is a no-no.