I have been reading up on ammo specs and to say the least, I'm a little confused. I hope someone here has some insight into some of my stupid questions. I read where the 9mm has a bullet diameter of 9.01 (0.355 in) and has a maximum pressure of 35.001 psi (SAAMI standards). The .357 mag on the other hand only has a bullet size of 9.1 (.357 in) and a maximum pressure of 35.000 psi. So it would seem to me that for all intents and purposes, with the exception of the .357 being .2 inches larger and the 9mm having 1 extra PSI, they seem to be the round. Would anyone else agree with this or am I missing something?