The old SAAMI pressure standards are stated in CUP whereas the new standards are rated in psi. For 357 Mag, the old standard was 46,000 CUP, which converts to 43,500 psi. SAAMI lowered 357 Mag pressure limits to 35,000 psi, which is a about a 25% reduction. 44 Mag old standards were 43,500 CUP, which converts to 40,600 psi. The new SAAMI standard is 36,000 psi, which is a little over a 10% reduction. There's still a lot of old "CUP" data floating around that was tested with the crusher method.
So ... the reduction in pressure standards was to extend the usable life of 357 Mag and 44 Mag revolvers.
