"the Americans likewise did not have .38S&W ammunition in their standard military supply chain, but the guns were largely issued to security guards at non-critical stateside facilities, so the guard could buy his own ammo at the local hardware store."
At some point, either during WW II or just after, the ammo did enter the standard supply chain, and was referred to at times as the .38 S&W Short, or something like that. Supposedly the OSS armed many of its field people with revolvers chambered for .38/200.
I have a book around here that has reprints of WW II/1950s era equipment tables. I'll have to look for it.
"The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza
Baby Jesus cries when the fat redneck doesn't have military-grade firepower.