used to shoot 9x23 long long time ago, used a specific 9x23 dies, the 9x23 is tapered same as 9x19, and a little bit longer than 38, , not sure if its a good idea to used 38 super on a 9x23 chamber. btw 9x19 shell plate is what I used.
almost forgot, 38 supers used same dies, except for the shell plate SC- 223 plates