For me, it's all about taking out as many variables as you can, especially on a gun I know I probably will be shooting long range. It will probably be okay your way but, it's something to second guess.
When sighting in, you eventually get to the point you say that's close enough. Any error how ever so slight at 100 that you accept, will be a lot more at 200, why not adjust from there?
After all, a 200 zero is only 1.2" high at 100, on an elk that's nothing. And I really expect to be seeing elk at much more than 100yds anyway. I would never want to walk around in the open country with a rifle set for 100, ever. Why even zero it there?
Journeyman, please read the 2 previous posts regarding zeroing at 100 yards. In addition to what they've said, among others in this thread, Doc Beach (Applied Ballistics) states, 'For a 100 yard zero you DO NOT need to worry about atmospherics.....If you zero at 100 yards, your zero is good for altitudes and conditions'. You mentioned 'taking out as many variables as you can'...zeroing at 100 yards is a good place to start.
You stated that 'when sighting in, you eventually get to the point you say that's close enough'. That doesn't necessarily need to be the case. If a rifleman is capable of consistently shooting (not having a 'wandering zero') you might find that in order to adjust the group's Point of Impact to the Point of Aim... you may not have enough resolution in the scope's turret adjustments. For example, you're POI is 0.13 MOA -ABOVE- the POA, your scope adjusts in 0.25 MOA increments, if you adjust your scope down 1 click (O.25 MOA)…..you'll end up 0.12 MOA -BELOW-. This can be corrected for by using your ballistic software to apply a 'True Range Zero'. Explaining this concept would make this post too lengthy. I'd recommend learning more about it. As a side note.....using the Ballistic-X phone app makes measuring group sizes and the relationship between POA and POI incredibly easy.
Getting a solid 100 yard zero is an important first step. Since this thread was addressed to dialers....It should be safe to assume that we're all using some type of ballistic software. I use Applied Ballistics, both on my desktop as well as in a Kestrel 5700 (for taking into account environmental conditions while shooting). There are many other really good ballistic solvers (Hornady 4DOF, Trasol, Ballistic AE etc.) However all of them are only predictive, based on the inputs they are given. They all need to be trued/calibrated to actual impacts on target at extended distances. Once again this is a subject that deserves a more thorough explanation than is reasonable in a forum post. In short, you plug in all of the required inputs into your ballistic software, shoot at extended distances (600, 1000, etc.) and then compare POA vs. POI. Use these differences to 'true the software'. In other words, you're telling the software the actual correction it should have given you under those circumstances (distance, environmental etc.). Once again, using the Ballistic-X app makes this process a lot easier.
You mentioned, 'I would never want to walk around in the open country with a rifle set for 100, ever.' From my perspective figuring out what you should dial your turrets to, yet still stay inside the target size from the muzzle out to distance is far more useful. Similar to a Max Point Blank Range. This should get you squared away from the muzzle out to 250-300 yards, depending on the cartridge, bullet etc. In the event you need to shoot farther than this bracketed distance.....you simply dial on to the turrets the DOPE required for the shot. It's not any different than what you'd be doing, if you were dialing up from a 100 or 200 yard zero anyways.
Having said this, I feel this approach is kinda bush league. If a hunter needs to take a fast shot that's over ~200 yards, I would argue that getting into a stable shooting position will take longer than dialing a turret a couple of clicks. Remember, distance to the target should give us time and opportunity to make a well executed shot. If you don't have the time to do this....you should most likely reevaluate the situation. 'Wing shooting' is for the birds.
I live and hunt in Alaska, I understand hunting in open country...sheep in the alpine and caribou on the tundra. I also understand hunting in areas with limited visibility...moose in the trees and deer on the islands. Having a 100 yard zero and a scope with the ability to dial an elevation correction has been a great approach and a valuable system.