Lets Do A Run Down For Future Clarity Shall We
.40 cal glocks can be converted to fire 9mm and .357 sig and .22 LR. It is said that 9mm mags should be used for the 9mm but the .357 and .40 are interchangable. If I were going to CCW it that way I would most likely buy the appropriate mags. I currently own a G23 and a G27. I purchased a G32 .357 barrel and can now run that caliber in both guns with no other modifictions. The 32 barrel acts as an extended length barrel in the G27 and its now my woods gun in that configuration. G23 is a dedicated HD pistol The .22lr requires a conversion kit. 9mm requires a conversion barrel and 9mm mags. Some say 9mm will function in a .40 mag I say BS.
.357 sig glocks function exactly as above. They can be converted to run .40, 9mm, and .22lr. The .22lr kit still applies as well. 9mm still reuires 9mm mags and a 9mm conversion barrel. Note a conversion barrel. YOU CANNOT RUN A G19 BARREL IN A G32 for example. The conversion barrel takes up the extra space in the slide left by the smaller cartridge.
.10 mm glocks can be converted to run just about every caliber it would seem. The larger frame size and slide demensions allow it to run .45, 9mm, .357 sig, and .40 caliber all with the proper conversion barrel.
In summary if you are going to CCW it converted at the very least have the proper mags. (My .40 cal mags stay stock while .357 sig mags have blaze orange markings on them. This prevents wrong caliber in wrong barrel issues)
I would suggest that the OP post here exactly what he or she is trying to accomplish and we can move forward from there.