One thing about CUP, that does not equate nor does it corelate in any way to PSI. Case in point, 42,000 CUP in a 6.5x55 Swede is about 52,000 PSI, while 35,000 CUP in a .45-70 is about 35,000 PSI. It's for this reason that I wish they would drop CUP entirely.
Not so.
https://www.shootingsoftware.com/ftp/psicuparticle2.pdf
