different barrels in g23
 

i just bought a g23 gen 4. can i just change barrel and shot 9mm and 357 sig. if so what glock barrels should i use.

If you have a Gen3 Glock 40 you can simply drop in a 357 barrel and be off to the range.

No, a standard Glock 9mm barrel is not the same. The barrel hood and barrel diameter is a full .022 smaller. Pick up a genuine 40-9 conversion from LWD and be done with it!