I am going to have to disagree with Tuner about the ejector. Don't worry, I don't intend to make a habit of it.
I have seen, (and currently possess), 9mm's which had an extended ejector that would be too long for a loaded .38 Super to eject. This would not stop you from firing, since that is when we eject empty cases. It would make it difficult to unload without firing, however.
I have swapped .38Sup to 9mm, and also 10mm to 9mm. The last one is supposedly not real reliable because the 10mm breechface is a little bit larger, and the ejector is not extended like the 9mm. Also, the extractor is not proper either.
Still, at least with hardball, my Delta 9 has been reliable. In fact, when I was having extractor issues, it was more reliable in 9mm than it was in 10mm!:banghead:
My latest project is a Colt .38 Super slide, cast Caspian frame. This is the one with the extended ejector. Right now, it has a 9mm barrel. Soon as time permits, I will shorten the ejector and install the .38 Super barrel.
As Tuner notes, I may have to tweak the extractor at that point.