I'm surprised almost no one is mentioning hunting @ 1000 yards? Aside from enough energy to properly kill, what about accuracy for shot placement? Now I don't travel in the world of custom rifles and custom reloads, but it would seem that if you're trying to hit a kill zone...about the size of maybe a large dinner plate, that any amount of wind would drift the bullet and cause a wound, not a kill. And we're also talking about 'in the field'..not some benchrest rifle with benchrest conditions. And from what little I know, would humidity and barometric pressure have some factor at these distances? And the wind you measure where you're shooting from may not be the same wind over a bullet path that long.
Maybe I'm older and out of touch with these sort of things, but hunting @ 1000 yards? I don't have those skills/equipment, so it's either get closer or don't pull the trigger.
Once a person starts shooting long range they find out what they need. Like the gunsmith question. A better guide. Practice will tell you what you need. With practice you find out all kinds of things about you and your setup. One thing is with practice you learn the wind and how it acts. With enough experience you will get a good feel for it but every place is different. A person can be the king on their section but an utter failure when they travel to hunt.
Use enough gun? I am a fan of going big. The 300wm is the smallest I will shoot at big game. Coyotes as having no life rights in my book I will shoot at them with anything I have with me. It still needs to be a safe shot. I prefer the 338LM for this shooting with the 300rr SMK. The 300gr smk is a very good bullet.
It can be hard to get a safe spot to have a safe shot. Here are my general rules for hunting long or longer range shots.
Nothing happens fast if it is do not shoot.
Stay on the scope after a shot. Now is not the time for high fives and jackass behavior.
Work the bolt and be ready to fire again.
When in doubt shot a second round.
Hold in position just like bow hunting.
You should have a spotter they should be ready to shoot also.
Pride should not play any part of your decision to shoot. Cold facts are it.
As to practice do it. As often as you can in every condition that is out there. I never fire more than 3 shots from any one position. In practice if you miss figure out why. If you fire two shots and they both hit the same spot well you know you are the problem. Shooting groups at distance can be fun it does not truly help you. Trust me I found this out the hard way.
The real fact of shooting 1,000 yds is nothing is ever at 1,000 yds. You need to practice much farther than you plan on hunting. Do not forget close range shots are good as your PK is very high.