Ive been away for a while and just saw this post. I have a Star Super in 9mm Largo. the Info sheet I got with it says that the original mil chamber was sized to allow the use of other 9mm rounds in an emergancy only. this was so that on the battle field they could use any 9mm rounds they could find. altho it will work, I would not do it. The pistol can safely fire the millitary rounds that you can find, but to do it they will be headspaced with the extractor being the only thing holding the round in place. it wont be very long before your extractor fails. as far as shooting 9x23 Win or 38 supper, these fire at a much higher pressure. I tryed shooting my supper with the spring kit with 38 supper, and it realy battered the slide back and bulged the cases. [ to much pressure.] I then changed the barrel to an after market chambered for 9mm P. After a little fitting it works fine and is very accurite. I did this back when largo was difficult to find , today I might have left it alone. DR.