On woodchucks I'll shoot & kill them at up to 500 yds where I hunt them. Just don't have a place to hunt them that would allow longer than 500.
On predators I've not shot over about 375yds, though I might depending on the situation such as a large yote standing.
On mule deer the longest shot I've made was just a bit under 700yds. Not 800-1000 as the OP asked, but farther than really sane. All other mulies have been between 25-240yds.
On whitetails the longest is 200 & only two of dozens of them were beyond 150yds. Where I hunt and a rifle can be used, the cover is thick enough that a shot gun with a good rifled barrel and sabots can cover most shots. One of the two I've taken over 150 was in fact with my SBE in a shotgun only area.
I think there are far, far more long range shooters now than in the past. Far better powders & more streamlined bullets combined with superior barrels & optics have allowed for this. I work with a man who's a member of the "750yd club", done on P dogs.
45 yrs ago when I was starting out a 700yd shot was considered a myth by most & anything over 400 claimed was taken with a large dose of salt. Now it's clearly still a long shot, but far from the realm of myth. I'm amazed at some of the shots I've seen that were filmed by some of the guys who post such on U tube, hunting CD's, or on TV for that matter. In fact I rather enjoy watching some of these long range prairie dog shoots & predator hunting as well. Some highly skilled folks out there now with gear to reach WAAAAY out there.
I've a 600 yd range on my farm & I practice often. Yet it's different when the target is living & will suffer if I'm not DEAD on. Yet those vids and this thread have me thinking again about a fast twist 22-243 or some such......
But only for varmints or predators, I took a deer once at crazy range...that's enough for me.