I think there was 7-9"s of penetration on an elm tree.
I have some hardened balls to test in a oak tree.
The ability to use hardened balls in a muzzleloading gun, as opposed to having to use dead soft conicals in a muzzleloading
rifle, was the reason conicals were not the preferred projectile for large and dangerous game, until large bored and strong
enough breech loaders were invented that could use hardened conicals. The soft lead conicals lacked penetration on the largest
game, just as soft round balls did. Balls could be hardened, but not so the conicals and still provide the requisite accuracy.