Not true. A .357 cartridge will slide right into a pistol marked .38 or .38 special and it will fire. The problem isn’t that the .357 cartridge won’t “go in” a .38 the problem is that a gun made for .38s or .38 specials is not made to handle the pressure. It might blow apart in your hand.
A .38 Special gun will not chamber a .357. The .357 case is 1/10th inch longer to keep idiots from blowing themselves up.
Exactly