First, I agree with the cz accuracy premise. I have experice with two more cz recently purchased 527 rifles. Not only are they sub moa, (sub 1/2 moa even), that is with factory ammo with very little trial and error. These guns are not rock bottom cheap cost, but a great deal when considering the product. That is nice walnut, (not just walnut, but nice walnut) polished and blue steel. Classic mauser actions are more effort to machine than cylinders like Remington or Savage. The guns look as good as they shoot. Same for the 550.
You know savage will produce both lemons and tack drivers. I propose the accuracy results from 2 simple steps. First: attention to detail. Such as replace worn tooling, better tooling, optimize machining for finish rather than just speed, operators who might actually qualify as machinist than just button pushers, etc. Second: inspection. I dont know how, but I am sure there are ways to quickly look inside and measure the chamber & bore. And, honest test firing.
Now toss in labor costs, pro business tax policy(?), worker pride, good management. All speculation, what ever they do, it works. I doubt they are any real secrets.
I know its not all rosy with CZ. They had some issue in the past. I also believe the current 455 rimfires are less refined and less accurate than the former legendary 452. The new 557 maybe a fine rifle, but it lacks the esthetics (and features) of the fine 550 mauser action and the excellent set trigger is gone. The rim fire is no longer offered with a set trigger option (old 453). On balance the company seems way ahead of the "made in usa" competition. The Tikka is fine for plastic.
Come back in 10 years, may all be different.