Steve in Allentown quoted TRX302 saying:
"JMB's original, preferred .38 cartridge design was rimless. However, Hercules had problems ramping up production of the powder they'd sampled to him, and in order to get the performance level to spec (125 grains, 1400 fps) Colt had to crimp the bullets so hard they would no longer headspace on the case mouths as intended. So Browning added the rim as a stop-gap so the gun could go into production.
Colt made some bad material and heat treat choices, and the .38 ACP was beating guns to death out in the hands of customers, so they backed *way* off on the performance, down from .357 Magnum to .38 Special ballistics, more or less. They later re-released the original loading, but still with the rim, as the .38 Super.
The 9x23 Winchester is, basically, the .38 Auto as JMB intended it to be."
I am not going to pretend I know the history involved here, but this sounds dubious to me. I don't think anybody was fooling around with pistol cartridges with 357 Magnum levels of power back then except that guy who designed the Webley Mars pistol, which was a huge gun built for maximum strength. Look at the lengths S&W went to when they introduced the 357 Magnum some 30+ years after the 38 ACP - putting it in a special, limited, registered edition of their biggest revolver, and selling it at a very high price. It was considered a gun for a limited audience, not something suitable for military issue, which is what Colt and Browning wanted back in 1899.
Nope, I can believe that the first version of 38 ACP developed about as much power as 9mm Luger (~350 foot/lbs) and that they then backed it off to about 310 foot/lbs, which is the standard for the 130 grain ACP load now. I cannot believe that it ever developed the 580 foot/lbs of the 9x23 Winchester, especially given the known problems of damaging 38 ACP automatics with 38 Super loads.
Standard velocity 38 Special loads are about 200 foot/lbs. If they were going for that, they missed badly.
As usual when I disagree with people, I stand ready to be schooled.
PS - When I refer to power, I mean kinetic energy. You may mean momentum. What we should really be talking about, probably, is max chamber pressure. 9x23 Winchester is a 55,000 psi cartridge. Both 38 Super and 357 Magnum are around 35,000. I really don't think Colt and JMB started out at 150% of that for 38 ACP.
PPS - a poster here at the High Ground (Driftwood Johnson, maybe?) has remarked that neither S&W nor Colt heat treated steel until the 1920's. 38 Super and 357 Magnum pressures may have become possible only after that.