38 Super (+P) is 36,500 PSI & regular 357 Magnum is 35,000 PSI
But with the flash gap and longer chamber of the revolver I doubt the pressures in a .357 Magnum, using .38 Super ammo, are even equal to that of the .357 Magnum round.
But gang, can you visualize a top break stainless revolver using moon clips and .38 Supers?
Or, since the round is shorter than the .38 Special, a 640 centennial with shorter frame and cylinder than the original Centennial but in .38 Super and moon clips?
That would be one heck of a CCW pocket gun! And DPX .38 Super ammo is available!