Cool, I looked at that 460 Rowland page a few weeks ago and they didn't have all that Ken Kempa data listed. Quite interesting but also disappointing, the light 160gr solid copper bullets show slower velocities than the 185gr jacketed lead bullets. I wonder how much of that has to do with bearing surface?
I imagine the 160gr copper bullets have considerably more bearing surface than the stout 185gr jacketed lead.
I've loaded a decent amount of 185 XTPs for the 460 and just from looking at online pictures 
of the 120gr Lehighs even they seem to have a bit more bearing surface than the 185s.
The other issue I may have to deal with in the Lehigh extreme defenders is that they were certainly designed for a 45 acp case, I will be seating to the same OAL with the 460 but the 460 case is longer and normally requires a crimp. My guess is that the case and crimp will come up and cover the base of the "flutes" in the Lehigh bullet, not sure what kind of issues that will cause.
