This information came from the ANSI/SAMMI Z299.3 - 1993 Manual:
(American National Standards Institute)
(Sporting Arms and Ammunition Manufactures' Institute)

Pressure Limits - (psi/100)

.356 TSW 147 FMJ
Maximum Average Pressure (MAP) = 500
Maximum Probable Lot Mean (MPLM) = 516
Maximum Probable Sample Mean (MPSM) = 540

That is to say 50,000 psi, 51,600 psi and 54,000 psi Max.


The only other pistol cartridges that I show the same or higher are;
9 x 23 Winchester 124 JSP
(MAP) = 55,000 psi
(MPLM) = 56,700 psi
(MPSM) = 59,300 psi

454 Casul 250 JHP
(MAP) = 65,000 psi
(MPLM) = 67,100 psi
(MPSM) = 70,200 psi

475 Linebaugh 400 JHP-XTP
(MAP) = 50,000 psi
(MPLM) = 51,600 psi
(MPSM) = 54,000 psi

500 S&W Magnum 275 Solid HP
(MAP) = 60,000 psi
(MPLM) = 61,900 psi
(MPSM) = 64,700 psi

Regards,
BM1