Found This Online...

Shooting .38 Super ammo in a .357 Magnum/.38 Spl revolver.  Is it possible?  Apparently, it depends on the firearm and ammo used.  Is it advisable?  Questionable.  See for yourself, link to the video is https://www.youtube.com/watch?v=dKvITAIEorI

38 Super should not be used in a 38 Special. The 38 Super pressure (36,500 psi) has twice the pressure of the 38 Special (17,000 psi) and exceeds even the 38 Special proof load pressure of 27,000 psi.

Seen it done by some guys at the range who didn't realize they had the wrong ammo for their 38 SPCL revolver.  Fired okay but the rim would slip past the ejector star when ejecting.