I can use the 40 mags for the 357 too so I read on the internets. If not I can buy the Glock Sig mags too like I had to for the 9mm. Interesting my Gun Shop never told me I could do any of this, found it all out looking for parts at glockstore.com but not for this.
I just read that a fellow had his shop ream a 40S&W barrel for an M2 to 10mm!