Oh, I like moon clips... I even have a PC 629 that is factory cut for moon clips.
The only time I have shot a rimless cartridge in a revolver without moonclips was to simply determine if it could.
The 9mm is a tapered case, s&w should be able to get the chambers close enough to not need moonclips to fire, they used to. My 547 (among others)works just fine without. To me, it's just a mfg cost effectiveness issue to make the chambers deeper than required, and it sorta bugs me.

Federal made a rimmed 9 mm cartridge, but it was rather short lived.