I've come across dozens of sources on the "internet" stating the .357 magnum in 125 JHP as the most effective handgun caliber and load in existence for self defense...
Do the terminal ballistics of this load really stand out that much greater compared to the plethora of other handgun caliber loads? If so why? And if not also why?
There is only one original source for this claim and that is Marshal and Sanow. No one else ever claimed it to be true. The "dozens of sources" all go back to the only original source for this claim and that is M&S. The work of M&S on their "One Shot Stop" statistics is more questioned than accepted.
The .357 Magnum made it's reputation with various 158 gr. SWC rounds for about 40 years before a reliable 125 r. jhp was introduced by Lee Jurras and Super Vel ammo in the mid 1970s. That round started a certain debate about which bullet weight was best in the .357 for defensive use. But the .357 already had a well established reputation as a hunting and defensive round prior to the introduction of the 125 gr. jhp.
Even then M&S did not claim that all 125 gr. loads were "the most effective" they claimed that certain brands of ammo loaded with specific bullets were, particularly the Federal and Remington loads. They also granted the 96% rating (the same they gave that 125 gr. 357 load) for some 45acp and some 40S&W loads. Certain loads of the 9mm trailed these by only a few percentage points.
So do the "terminal ballistics" of this load stand out a great deal more than other rounds? No not according to M&S and they are the only source for that one shot stop info.
If we look at what the term terminal ballistics actually means,which is what a bullet does after it strikes, than bullet construction plays an important often critical role. Depending on the caliber, bullet type, weight, velocity, etc. a number of service calibers will do equally effective jobs. So again we can say that no the .357 Mag with a 125 gr. load does not stand head and shoulders above some other rounds and loads.
The 125 gr. loads from Federal and Rem. are good loads for defense but they are also one choice from a number of good choices. Type of gun, how well the shooter can handle the load and their gun and shoot it, etc. play a more important role.
tipoc