I can sort of respond to that, as a result of an abortive effort on my part to come up with a full-sized semi-auto the fires .380 ACP. I knew to make it a real firearm I would have to invest in having a custom barrel built, and before getting into buying an expensive barrel I wanted to see if I could find a spring combination that would work with .380 ammo.
So my first attempt was to just shoot .380 ACP from a 9mm pistol (headspacing on the extractor). It fired, but there wasn't enough energy to cycle the slide even with a VERY light recoil spring. The brass was very black, and from the case web all the way to the mouth was badly stretched. So obviously a 9mm chamber is too big to work with .380 brass.
So I repeated the experiment with a .38 Super, and essentially got the same result. It fired, it wouldn't cycle the slide even with a VERY light (cut-down) recoil spring, and the brass was so stretched that I wouldn't consider trying to resize and reload it.
In the end, I bought some 95-grain bullets and reloaded 9mm cases to approximate the performance of .380 ammo.
So ... the point being that a .38 Super chamber is smaller than a 9mm chamber, and a .380 ACP chamber is smaller than both of the above. I would be extremely reluctant to try resizing loaded 9mm rounds down to fit a .38 Super chamber. The part that needs to be resized is the web, the thickest part of the case. I can't make myself think there's even a slight chance of that being successful.