When I carried 1911s, I wound up replacing the Ceiner conversion slide with a Ruger 22/45, and when I switched to M&P9's, I got an M&P22. I'll be picking up a rimfire Glock slide, but it will probably wind up living on my Glock 32 frame rather than being swapped on and off my carry G19. Generally, I shoot my carry gun in classes and matches and other than that, I'll dump the mag for fresh rounds if it doesn't get shot in a couple months. I try and minimize the administrative loading and unloading with it.