Re: 100 yd or 200 yd zero???
Rimfires zeroed @ 50 yds. Centerfires @ 100 yds. I use the turrets on both, as well as mapping the mildots/hashes for all comeups. I have standardized all my scopes to Mil based reticles. So I can either dial, or use the correct dot/hash for faster shots.
It is easier to get a good accurate group @ 50 yds for a rimfire and 100 yds for a centerfire, than anything further. But I do test the scope adjustments and rifle at long distances to prove my data.
Before the invention of repeatable turrets, and my use of a mil based reticle, I used a 3" high zero @100 yds on any gun expected to reach out more than 225-250 yds.
It's so easy today, with good repeatable turrets, FFP scopes, mil based reticles, laser rangefinders, and afforable chronographs, compared to 20 years or more ago.
Bob