Yes, they're kidding about the "actual lightning"
.
But, a good 357 round is a hell of a good stopper.
Buffalo Bore and Doubletap compete for the title of "most thermonuclear ammo". Both have 125gr 357 JHPs that can hit 1,600fps from the better (read: faster) 4" barrels, such as the newer S&W tubes and most Rugers. That's almost 800ft/lbs energy.
I shot one of these monsters at a bowling ball at 20 paces. Gun was a Ruger New Vaquero 357, 4.68" barrel. Split that thing in half, sent pieces of the concrete innards back past my feet. The guy I was shooting with who owned the ex-ball said that he'd never seen a handgun do that to a bowling ball ever.
The projectile was a Gold Dot "high speed variant", which would very likely expand and hold together at that velocity. This is a serious manstopper of a load, one of the nastiest available.
However.
The 357 earned it's killer rep in the '70s when most hollowpoints didn't expand. Due to raw speed and energy, the 357
did most of the time despite primitive JHP designs. The Remington "full house" 125 is an example of that breed, still in use because it works despite being primitive as a stone axe. During that same period, there wasn't as much projectile development on the 41 and 44Mag, so despite their higher energy numbers the 357 was considered (rightly at the time) the better manstopper.
Today, there are some very good 44Mag JHPs out there that would probably hit even harder than even the best 357s like that Doubletap 125 that flattened that bowling ball.
But...the best 357s leave the 9mm+P, 40S&W and many other slugs in the dust.