It's not uncommon for folks to kill deer at over 600 yards with a 308 Win and a good LongRange bullet. A fella I hunt with uses his 308Win on elk, 2 years back now he killed a cow elk at just over 500 yards with the 308Win. one shot.
There are several things to keep in mind. Firstly, when folks talk of remaining energy they often make the mistake of using Standard Temperature and Pressure (STP) (0 feet above sea level and 59 degrees) when looking at ballistic tables. One needs to examine the charts based on local criteria, 5,000 ft ASL and 40 degrees, or 11,000 ft and whatever.
Secondly is the difference in animal behavior when humans are not detected/able. 400, 500 yards on an unaware animal and their behavior is very different from an animal hit at close range.
Short answer is: hit them in the chest and they die no matter the distance.