Mr. Shepard, I own a G23 and, reading on GT, there seems to be a way to easily change calibers from the standard .40S&W to .357 sig to 9MMpara. I am very interested in owning a 9MM Glock, and mildly interested in owning a .357sig Glock. Is there a safe, easy and relativley inexpensive way to make my G23 shoot 9MM and .357sig? I am aware that it should be no more than a barrel change for the .357sig, but is it the same for the 9MM? Obviously, the mag and barrel should change for a 9MM, but is there something else? Springs perhaps? Thank you in advance for your response. It will be nice to get a response that is not an opinion, but one that can be considered as close to Gospel as possible.