Ah, yes, that would be one of those no-room-for-error scenarios. My very first job I ever got was working for the Watervliet Arsenal, the only place in the US that still manufactured tank cannons. I typed up the records from HR "interventions". I still recall the guy who was being fired, and protesting that he was skilled enough that he didn't need to use the fancy calipers to bore the hole in the gun (which is why they were firing him). So they measured his work. He was 1-10mm off on each. It doesn't sound like much. But in battle conditions, those tank guns could blow up instead of firing, at worst killing our soldiers, and at best disabling a very expensive piece of equipment.