if you are getting a revolver, unless you are buying a really lightweight snub for carry- buy a .357, not a .38. Any .357 can fire either cartridge, as the dimensions of .38 special and .357 are identical except the magnum is 1/10 of an inch longer so it can't accidentally be put in a .38.. if you have a .357, you can fire either cartridge, which also means the gun will likely be worth more should you ever need to part with it..