Regardless of ballistic gelatin tests, and “meat target” tests, the best data comes from the results of actual street shootings. For a long time now the .357 Magnum 125 grain JHP has been regarded as a gold standard. This is a high velocity, light weight bullet with a hollow point design. I have thought that similar (or better) results might be had from a 10mm 135 grain JHP. Seems logical but, again, there is pretty much no real world street shooting data available to support that theory one way or the other.
So we are always left with speculation regarding street effectiveness of many combinations of caliber/bullet.
What we do have are ballistic gelatin and “meat target” tests and, although they have their drawbacks, they do tell us some things.
My son, in junior high school, had to do a science project and asked me my advice. He and I chose a penetration and expansion test using a .44 Magnum revolver against wet phone books. I loaded 240 grain bullets at four different velocities, shot them into the targets, retrieved the bullets and measured both penetration and expansion. We plotted the results and put the retrieved bullets together with the data on a board. The teacher was shocked (but gave my son an “A”), and told my son never to do that again. Anti-gun, of course.
All of this conversation about ballistics, calibers, and bullet types/weights is fun and I appreciate everybody’s contributions to this thread. Thank you all and Hans, your comments have merit in my eyes.