This video explores the modularity between the GLOCK 19X, G45.5, and G23.5. It also compares the G23.5 and the G23.3. There is no shooting and nothing in the video should be inferred to be safe or a good idea. "Function checks" are not adequate to prove reliability. Consider this academic.
The Gen4 G23 would be more interesting in regard to modularity with the Gen5 G23, but I don't currently have one. The recoil spring assembly (RSA) in the Gen4 is the same size as the Gen5, so the channel would also be the same (or close enough to not cause problems). It is what it is.
![](https://s2.save4k.ru/pic/vFg8wku4ib0/maxresdefault.jpg)