BudsGunShop.com - S&W 442 work with moon clips?

This is the standard 442 (no moon clips). The one you are thinking of is a Performance Center Revolver called the 442-1 Moon Clip model. You can have the standard 442 cut for moon clips after you buy it. It's a good option for a carry gun with a short barrel because it's impossible to tie the gun up by getting a case under the extractor with the moon clip setup.

Moon clips are actually required for most revolvers chambered for semiautomatic calibers like 9mm, .40 S&W and .45 ACP. These calibers use a rimless case that is designed to feed and extract more efficiently in an autoloader. The moon clip rides inside the indented groove in the case, and functions like a cartridge rim to set the headspace for the cartridge when chambered. Revolvers using rimless cartridges cannot be fired without moon clips.
The moon clip can also be used with traditional rimmed revolver cartridges such as .38 Special, .357 Magnum, .44 Special and .44 Magnum. With rimmed cartridges, moon clips are not required, but may be used to increase speed and efficiency in loading.
However, unlike a revolver designed to fire a rimless cartridge, a revolver chambered for a rimmed cartridge must be specially modified to allow the use of moon clips. The cylinder has to be cut so the moon clip sits flush on the mouth of each chamber without changing the head spacing of the cartridge.