I have moon clips from TK custom for .38/.357 in both a S&W M60 and S&W 686. The cylinders are machined to use clips, but can of course be loaded without clips. Reloading a revolver with moon clips is substantially quicker than without. And the rounds are easy to carry around in clips too. Just look at some IPSC revolver videos on YouTube.

http://www.tkcustom.com