I converted a friend's 3" STI 9mm Elektra to 9x23win...
works great, still quite shootable with the hot Winchester ammo.
I am looking for a good deal on a used 9mm Defender, for a .38 Super conversion. I also want to shorten the frame like a Wilson Sentinel, and lighten the gun as much as possible.
I built a 3.5" Officer's sized lightweight .38 Super (ramped barrel) a few years ago. Fairly mild recoil, nice shooting package... so I think slightly smaller/shorter/lighter is doable.