Yes, seems the main difference (besides different 108 bullets) is that viht is much more conservative. Generally speaking the N5xx series powders seem a little higher energy and can produce a little more velocity than a lot of the single based hodgdon extreme line. From what ive seen 565 is pretty close to h1000 on charge/velocity in many cases. I've come to find a lot of the single source data pretty poor for comparing apples to apples and this seems like a prime example of that. Edit: also just noticed they have a higher h1000 charge than retumbo, that is also odd.. Not sure if that has to do with powder density and retumbo taking up too much volume in that case or what but ive never seen that.
Yeah, for starters hardly anybody is going to hit a 1 MOA target at 100 yds 90% of the time with their hunting rifle from a bench for a laundry list of reasons. A ton of people can shoot sub MOA 3-5 round groups on command but getting them centered on POA is a whole nother thing. That's at 100 yards. Not in the same universe as being able to read the wind at 1000 yards, have ammo that is consistent enough, hitting the right velocity with the given temperature/bore condition at any given time, having the right dope for the current density altitude, and equipment that adjusts perfectly..
Used to be pretty into the long range hunting thing until I realized that once you get out a little ways, the conditions can really mess with where the bullet is going to land and in order to understand that it takes an inordinate amount of practice. The more ive learned on all the ways i can miss, the shorter i think is reasonable to shoot, and all the people spraying and praying at long distance because they hit a gong one time at that distance just pisses me off.