I remember with the 460 Weatherby Magnum, I was loading and shooting Barnes round tip solid bronze 500 grain bullets.
I had it pulling a 3/4" group at 100 yards (bullet holes basically overlapping each other).
We went out and lined up three hardwood trees that had differnt points of impact (first tree, center, second tree, one side, third tree, other side). The trees were not real large, probably 5-6" in diamter. There was a freshly-hayed field about 20 yards beyond the trees.
One bullet went perfectly straight through all three trees and made about a 10' long divet in the field - perfectly lined up with the shot. When we retrieved the bullet, other than rifling grooves, the nose was almost perfectly round, like new.
That would be SOME PENETRATION on an EXTREMELY LARGE GAME ANIMAL! Probably clear through from chest to stern, or darned near through!