>>49788547BBTI universally measure the barrel length to the breech when doing their tests so a .357 mag gun could't possibly have less than 1.29" of barrel length as this is the minimum necessary to accommodate the cartridge case. For a revolver, length of the cylinder can't be less than 1.59" due to OAL of the cartridge and you'd probably add a barrel to the front of the frame instead of having the cylinder just hang on the front like a pepperbox, the shortest barrel of a revolver is around 1.875"(i checked S&W site) so you it's impossible to have a factory made .357 magnum revolver with less than 3.5" barrel if measured by pistol standards.
>>49788553>.357 is loaded to higher chamber pressures.357 mas pressure is the same as regular 9mm - 35KPSI. 9mm +p is higher pressure so in this case people's guesses are right, although more slow powder at the same pressure means that at any given barrel length the velocity gain and muzzle velocity will be higher, with a rare exception of slower powder being slower to get to max pressure.
