I have used .38 Special cases in a .357 revolver. It works OK. No problems at all other than cleaning the crud out of the chambers from firing a shorter cartridge. I always use jacketed or plated bullets and do not shoot lead bullets unless it is necessary. You will probably want to clean the chambers well with a good brush after shooting a bunch of .38 rounds to make your longer .357 cases easier to load.

To avoid cleaning out the ring of crud I do not shoot the shorter cases in .357 or .44 revolvers anymore.