This high shoulder shot (X2, one for insurance) with a 275 gr. X in .475 Linebaugh put her down with authority fully equal to any 400 gr. bullet I've used. In general, light for caliber Xs penetrate better and cause more damage (from expansion) than heavier bullets in any caliber.
Same thing with this brown bear and a 375 gr. X in .500 S&W. One high shoulder did him in. Paid the insurance with #2.

The Xs on both animals were expanded under the skin of the off shoulder.
Same results on a croc with 185 gr. X in .325 WSM XP, but with a spine shot.