Hmmmm, clips, moon clips and half moon clips are meant for use with rimless cartridges to allow them to be used in revolvers. Most are in caliber 45 acp. The 38/357 are revolver rounds and using speed loaders, all chambers can be loaded simultaneously and with a revolver all the cases can be ejected simultaneously, which is what happens with the use of moon clips and the like.
IIRC there is a S&W that is a medium bore, for some reason the 38 Super comes to mind, that either uses moon clips or cylinder mounted spring style ejectors, or the 356 something - they are specialty revolvers I believe but maybe someone else here knows of them. There is also or at least used to be a 9mm j-frame but I don't think that is still available.
If you were (possibly) thinking of a speedier way to reload or a easier way to carry extra cylinders full of ammo, you may wish to watch some of the speed shooting competitions on the shooting channel, or get some videos of some of the falling plate or IDPA competitions where some of the shooters use revolvers. Check out what they use for reloaders and how they carry their spare loads. Some of those shooters are incredibly quick and you might be able topickup on a few ideas.
Tryin' to help. Merry Christmas.