I hunt in some pretty wide open spaces. 90% of my blacktail deer hunting is above the treeline where you can see for miles, and mainland caribou are generally found on wide open tundra.
When I was younger, and much stupider, I wanted to make those long shots and I was into the huge scopes and spent way more time than it's worth trying out different reloading recipes for that accuracy. No matter what you do though, there's wind and there's range estimation errors and heavy breathing from hiking up that mountain, and just plain bad shots. So, there's crippled and lost animals in my past that taught me a lesson.
You owe it to the animal you are hunting to get close enough for a sure kill. Maybe that means you have to backtrack or make a big half circle of a mile or so, or low crawl through brush - and maybe after all that, the animal isn't there any more. Hey, that's hunting!
For hunting at ethical ranges, you don't need a sub-MOA rifle. If you have to think about wind velocity and bullet drop of more than a couple of inches, you're too far away. Get closer. I like to get within 200 yards. I'll consider 300 if there's no wind, but around here that's a rare day indeed.
I'll exempt pronghorn hunters, etc, but for 98% of us; if you're taking long range shots it's because of poor hunting skills. Sorry if that sounds harsh...