I've done a lot of testing of big-bore bullets in tough media (dry glossy magazines, plus wood planks and hard cover dry books). There were a few surprises, like a 500gr Speer African Grand Slam making only 6" penetration, lost the front core retaining 310gr (62%), and a 350gr TSX giving complete penetration, stopping at the last panel of the second box with two planks of wood between the boxes, retaining 100% unfired weight, and fully expanded at 18" penetration .
That's just one thing. A 330gr Barnes Banded passed through all of it and may still be going! A 350gr Hor RN was stopped at 4", lost its core and the remaining jacket weighed 51% with some smeared lead attached... and so on.
The point? There are too many variables to be pontifical! Impact velocity, media type, bullet weight, construction and shape are all players. Some high velocity projectiles penetrated the most and others were defeated early on due to their construction and shape. A 480gr Hor DGX passed completely through, hitting a ledge behind leaving a perfect .458" imprint and that bullet was never found along with a few others. And so on...
I've used a variety of bullets (hardcast, mono-expanders and regular cup-and -cores from my .45-70s and .458s on black bears, and all I can say about that is Big Bores will stop 'em right there!
