Yes, that's the way that I have been told to zero in the past. Again. I know the 200-yard needs work, I am a beginner shooter with a bolt gun and that was maybe my 5th or 6th time shooting one as well as my first time shooting past 100 yards. I have experience shooting pistols and AR-15's because of work and have been an archery hunter for the past 20 years or so.
I plan on setting the zero on both guns at 200 yards and dialing out past 300 yards, once my shooting improves.
It's been said, but I'll reiterate. For the purpose of load selection, I would shoot 10-shot groups at 100. Don't worry about where they land on the target, you're just trying to find a load that makes acceptably tight groups. I'd be looking for 10-shot groups under 1.5 MOA; if you're a new shooter, maybe sub-2 MOA is more realistic.
Once you find a load you like. I would get a very precise 100-yard zero, again using 10-shot groups.
Lots of reasonable arguments to be made for a zero past 100 yards (e.g., 2" high at 100, MPBR, etc.), but for me I just want a rock solid 100-yard zero. I think a lot of the rationale for zeros over 100 yards come from pre-laser rangefinder days. Similar arguments are made for super fast, flat shooting cartridges... it's helpful if you're guessing at your range, but not as important with the advent of laser rangefinders.
Here's some light reading on zero range:
https://rokslide.com/forums/threads/100-vs-200-yd-zero.257081/
As far as factory ammo selection goes, I think there's a compromise to be made between precision and affordability. At one end of the spectrum you have super cheap ammo that doesn't shoot very well (e.g., bulk FMJ military surplus stuff) and at the other end you have very expensive, very consistent ammo (e.g., custom match stuff). Try to find something in the middle that shoots acceptably well
and is cheap enough to shoot in volume. I would lean towards the cheaper side to be able to shoot more. Don't get balled up trying to find a load that is 1/4 MOA better than another, especially if you're a 2 MOA shooter... it just doesn't matter. If you're a 2+ MOA shooter (most people are whether they want to admit it or not), you've got a lot more gains to be made working on your form than chasing 1/4 MOA differences between loads. For example, I practice (and hunt) a lot with Hornady Frontier BTHP and Hornady Black A-MAX loads not because they're the most precise loads I can find, but because they're a good compromise between precision and affordability.
Here's another worthwhile thread:
https://rokslide.com/forums/threads...ice-posts-and-rifle-practice-shooting.165291/
Cheers