It's rocket science plain n simple.
I'm not in Ridge Runners class of long range shooters. I'd have to do some research and actually buy the set up to do that kind of shooting. That's a whole another bag of tricks. I do believe these guys can pit the ace at 900 yards. I've had the itch to play in that field for awhile now. 600 yards and under I'm confident in my equipment to know when that rifle goes off my hunt is over. Knowing is half the battle. So if you don't know you can always go find out. Start at the range not on game.
Once a person builds good shooting techniques the rest is rocket science.