Old thought process
Now all top tier centerfire pistol can manufactures build cans to me user serviceable. This also allows sub caliber use.
Example: Buy the SWR Octane45 and you can shoot 22, 9mm, 40, 45, 38spl, 357mag, 44spl, 300blk out subsonic, and 308 subsonic. Its also full auto rated and you can take apart an clean it. Whats not to like?