The 357 magnum that Python fires is a different round than the 357 sig this guy was supposedly shooting.
Correct, but they claim the same performance: 125 grain JHP at 1350 fps. I have one of each and I tend to believe it, although I would say the Python hits harder and farther. But I feel very safe with either of them. The Python just feels more familiar (since I have owned several in the last 40 year, and shot one of them loose.)