I have a 9x23/9x19 switch barrel pistol that John Harrison built for me on a Series '80 9x23. Just swap the barrel and FLGR (makes it easy to remember which spring is which and makes dealing with the 9x23 recoil spring much easier). The pistol uses a flat bottom firing pin stop to delay 9x23 unlocking, so the 9x19 recoil spring is pretty weak. Now that I have other 9x19 pistols, I leave the 9x23 barrel and FLGR in the pistol. If switching between .38 Super and 9x19, the extractor may need to be adjusted.