If you look at the history - - -
- -I believe you'll find that the .38 Spl originated in 1899 or 1900, and was indeed originally a black powder round. The same or following year, they began loading it with smokeless, but a great many shooters reloaded it with black powder.
If you look at the other medium power cartridges around at the time, the .38 Spl was a pretty hot number for its day. The .38 S&W, .38 Colt and .38 Long Colt - - Those were considered pretty powerful stuff, when compared to the various .32s in service then. The .38 WCF (.38-40) was about the only high power handgun round in that general size, and, really, it was more of a .40" diameter. It was conceived as a rifle and carbine round and Colt and S&W chambered their larger revolvers for it as a convenience. The other ".38" rounds were really founded on the conversions of the .36 percussion revolvers, hence the .357-inch diameter of the .38 Special.
The other .40" revolver round in that era was the .41 Long Colt, which flund a nice bullet of 190 - - 200 gr, but at a very sedate speed.
In a day when the .38 S&W, 146 gr. at about 740 fps, was considered generally adequate, a 150 to 160 gr. bullet at 860 was fairly toasty, and this was realistic in a day when a majority of revolvers above .32 cal had barrels of five to seven inches.
Remember, too, the .36 percussion revolvers, the "Navy" caliber guns, were still in widespread military use, right up to the inception of the .45 Colt SAA. James B. "Wild Bill" Hickock made his name with the Colt's Navy arm, which was really about as powerful as a modern .380 ACP.
Perceptions change as to what is "powerful."
With modern steel and alloys, and modern powders, the original .38 Special performance is easily surpassed. But there's always the nod toward those who shoot old revolvers, and also those who simply consider the "good, old fashioned, police special" load good enough.
Best,
Johnny