I imagine Darryl could give you the best idea, them Elk aren't much different critters for size.
I know a 338 300gr anything would do the trick, near or far, any angle... they ain't brown bear or even close. Matter of fact, if the shot was well placed in a Brownies shoulder I doubt he'd keep it from entering the vitals too, although I'd use a better constructed bullet, as I might be having to track him down afterward.