Good question. And here are my (2) answers (which may or may not have merit):
1) using moon clips means when you empty the cylinder ALL the brass comes out so that you can then reinsert a full load.
2) slightly less volume to carry without the speed loader.
The 940 is an awesome little revolver. It was S&W's 9x19 moon clip J-frame revolver. You can carry 2 full 9mm moon clips in the space of one loaded speedloader. More punch than a .38+P, too. So, uh yeah, I think it's a great idea even with other rounds.
For rimmed rounds, yes, you can usually still use the revolver without the clips and the extractor will work well. Non-rimmed rounds like 9x19 will usually work too, but not as well - for example, they do work (more or less) in the 940 without the clips - just extraction is a PITA and you could get the occasional light strike failure. That shouldn't happen using rimmed rounds without the clips, though - they should work as normal with or without.
Good question. And here are my (2) answers (which may or may not have merit):
1) using moon clips means when you empty the cylinder ALL the brass comes out so that you can then reinsert a full load.
2) slightly less volume to carry without the speed loader.
Gee Matt, that is another one of those things I have done. Only problem with it is trying to find a way to carry the loaded clips. The J frame clips are fragile and bend easy.
I did 2 Js so far a third to happen soon but I am still looking for a good way to carry the little loaded moon slips.
As for who? go to Moonclip.com and see Tom's list. Tom did both of mine so far but I will shop wait time for the next one.
Yeah, one thing I was looking for was a speedloader pouch that wasn't wide open around the top, so I could put two moonclips in there discretely. What I wound up finding was this little belt pouch, which neatly holds two loaded J-frame moon clips and looks like a cellphone or battery pouch (it is sold as a battery pouch). Inexpensive and well made.