Numbers
On my other blog, i have a long post about sports statistics. It has some applicability to shooting. Gunwriters often make the same mistakes that sports commentators do.
Both subjects share the same drive to reduce everything to a single number which picks the "best" cartridge or bullet for a given purpose. Sometimes it is expanded diameter, other times it is foot-pounds. For self-defense purposes Sanow and Marshall will give you "one shot stop" percentages that purport to make distinctions between 77% and 78% based on a relative small sample of events.
One key assumption in all this is that there in a clear-cut "best" and that it matters. It is as though the hierarchy of choices is shaped like Pike's Peak, with some loads or calibers towering over all others. But what if the better analogy is a plateau with multiple calibers having relative similar performance and none being the one best.?
Seyfreid referenced the records of a moose camp in Sweden which tracked the performance of rifles which ranged from 6.5 Swede to .375 H&H Magnum over many years of hunting. The surprise was that there was not any clear difference in performance across this wide spectrum of cartridges on what is a very large game animal. Most animals required on one shot, and most ran the same distance after being hit. Amazing, but that was what the records of hundreds of hunts showed.
Maybe, by 1910, gunmakers completed their mission-- they packed enough power into metallic cartridges to do the job and everything else has just been refinement.