Nice wish, but it will not work. Same question has been asked about Glock 17/19 using .40 barrel to the point of exhaustion. You can get a third-party barrel conversion for Glock 22/23 to shoot 9mm, but not the other way around. The reason is quite simple. Your slide opening for 9mm barrel is smaller and it will not fit .40 barrel. On the other hand, conversion barrel for 9mm to fit in .40 slide is thicker and outer diameter fits the outer diameter of the .40 barrel so it all works fine.