I'm 1,400 miles away from my loading data, but I can tell you that the Sierra Book's load shows best velocity with 4064. Realize that with that short barrel you're giving up around 200 ft/sec to 250 ft/sec.
At 400 yards, the trajectory of a 180-grain boat-tail is little worse than the 150-grain boat-tail. (I'm a Sierra bullet user.) So if you're zeroed at 200, you're gonna be around 7 or 8 inches low at 300 and around 24"-27" low at 400, right?
If you're unused to estimating range in big, open country, I strongly recommend buying a Bushnell 800 laser range finder.
Also, if you have access to some open country nearby, get yourself three sheets of cardboard around 5'x5'. (Check the back of a WalMart or ask at an appliance store.) Make a cut about 4'x3', centered out of one side. This gives you an "elk body". Set these at 200, 300 and 400 yards from your "hunt stand". Look at them through your scope. It may not be the best deal in the world, but it beats hell out of doing nothing.