MYTH? The 357 bullet that was designed to bust engine blocks: That round was manufactured until about 1960 or so. Nearly any current . 357 round will knock a hole in a modern car engine block.May 10, 2010
The High Road
Okay, I'm going to give you the benefit of the doubt here... The .357 Magnum cartridge was neither designed to pierce engine blocks, nor was it ever capable of doing so.
You may be thinking of the fact that .357 Magnum was known and praised for its ability to reliably pierce auto bodies and windshields whereas early round-nose .38 Specials had a reputation for being stopped by car doors if they struck one of the more reinforced parts of the door or being redirected by windshields of more slanted angles, but .357 Magnum cannot pierce an engine block.
Heck, not even the .500 S&W Magnum (which is currently the most powerful commercially available handgun cartridge) can pierce an engine block. Don't take my word for it though, Google it, folks have tested what can and cannot in fact pierce an engine block many times over, complete with unedited videos of said tests being conducted, and the results are honestly quite shocking just how sturdy an engine block actually is.
The .357 Magnum cartridge's supposed ability to pierce engine blocks is pure Urban Legend the likes of Winter Coats being able to stop small caliber handgun bullets or .45 caliber handguns being able to knock a man clean off of his feet.
There is a wide variety of folklore, myths, and legends in regards to the effectiveness (or lack thereof) regarding particular firearms/ammunition, all of which is (as the names suggest) exaggeration at best.
Furthermore, there is a lot of fabrication in the media concocted either for the sake of entertainment or sometimes to push a particular narrative for political purposes. So you really have to take everything you see or hear regarding firearms with a grain of salt.
To provide a personal example, for the longest time I carried a .380 ACP pistol exclusively because I had been mislead by things that I had heard online about how even standard pressure 9mm Luger was a powerhouse Military cartridge which offered the absolute best ballistics performance and how anything more powerful was either excessive, dangerous, or somehow offered no practical advantage, so being a simple civilian, .380 ACP seemed more than adequate.
However, as time passed and I learned more about firearms, I came to realize just how misguided I was, how inaccurate the statements I heard were, and just how many nonsensical statements are made on a daily basis on the internet by novices masquerading as experts. Now I carry a double stack semiautomatic pistol chambered in .40 S&W, a cartridge which is claimed by certain folks (who consider themselves experts and even make a living training/instructing others) to be so volatile that it literally tears guns apart, yet inexplicably offers no ballistic advantage over 9mm Luger.
TL;DR: Don't believe everything you hear about firearms because most of it is complete nonsense and always check your facts, lest you end up posting threads and arguing with folks based on complete misinformation.