I took a quick look at a ballistics table for a 180 gr bullet (a Sierra GameKing- not a particularly tough "controlled expansion" bullet, mind you, just what I have handy).... even with a BC above .500, which many of the controlled expansion bullets won't have, you are looking at more than 2 feet of drop @ 400 (more than 4 feet @ 500!) with a 200 yard zero ... and more than a foot of wind drift with a 90 degree 10 mph wind..... I'm thinking maybe a 180 gr bullet to 4-500 would be beyond the .308 WIN, particularly for someone who has never shot that distance.
It is not as simple as settling the crosshairs and squeezing the trigger at that range. You have to know your trajectory and the exact range, and be able to read the wind.... with a faster (and/or more efficient) bullet these variables are lessened, but they are still there.
TheGolden Rule of Tool Use: "If you don't know what you are doing, DON'T."