James B, I think that you are making my point!
In general the less a bullet deforms the greater the penetration, not the other way around. IMO, if you look at the wound channel from the 458 win mag and the 45-70 with a LBT bullet you will see a MUCH wider wound from the 458, especially in the beginning as the bullet sheds energy.
Clearly, a solid bullet that does NOT deform or tumble will penetrate further the faster you shoot it assuming it is shot through the same medium. A deforming bullet is a totally different animal in that regard.
IMO, Compare the penetration of a Nosler Partition to a non bonded bullet of the same profile/caliber and weight with an impact above 2,500 fps and the Partition will out penetrate the other 99 out of 100 times because it will not disintegrate. It will almost always lose the front core, but the expansion will almost stop whereas the standard bullet will very often become a bunch of lead and a separate jacket in many pieces ( depending on caliber).
edge.