you're thinking magnumIsn’t the .357 a higher grain count than a .38?
Never owned a revolver, so just wondering?
From the aspect of this article a true .38 would be a black powder cartridge bullet. So a few thousands larger projectile (.38) would naturally weigh more....
you're thinking magnumI have seen both 38 special and 357 Magnums loaded with bullets of 95 Grains up to 200 grains. Loaders uses different weights of both bullets & powder trying for better accuracy, speed and ballistics. Mostly for the never ending search for that elusive “perfect cartridge”. Original weight for the 38 Special was 158 Grain if memory serves.
I think one reason for the early 38 caliber designation was the popularity of the 36 caliber percussion revolver. Maybe even a marketing ploy since the 357 was actually a tad smaller than the 36 cal.
The 357 magnum was designed to throw the bullets at much faster speeds than the 38 Special. They did this by adding more gunpowder. Thus, the internal pressures, at combustion, are much higher. So much higher that it would probably damage a .38 Special. To prevent damage to the pistol, they beefed up the revolver shooting the 357 magnum. To prevent 357 magnum cartridges from being accidentally loaded in 38 Special revolvers, they lengthened the brass casing, so they won't fit in a 38 Special.
I've omitted a lot of details, but that is the fingernail sketch.
Oh yes, a 38 Smith and Wesson is a different cartridge than a 38 Special.