I agree that the newer cases don't have the capacity of balloon head cases.you would never get the 38 grains in it that it is supposed to have.
No I am not confused. Why Winchester named this cartridge this way is a mystery, or at least I have not found the reason. It should actually be aI agree that the newer cases don't have the capacity of balloon head cases.
Actually, the first number represents the caliber and the second number represents the charge weight. So it is 38 caliber with 40 grains of black powder.
However the .38-40 has a bullet that is actually .410 in diameter. Confused yet?
Here is some reading on the .38-40
http://www.chuckhawks.com/38-40win.htm