You may or may not have to adjust the extractor for the difference in the semirimmed .38 and the rimless 9mm. I have had one each way. I could not get to a compromise extractor setting on one, it is a .38 or a 9mm, but not both. The other would do fine in either caliber just by swapping barrels.
Your .38 magazines may feed 9mm, especially roundnose. Give them a try before buying new 9mm-only mags.
[This message has been edited by Jim Watson (edited 09-21-2001).]