Mostly I call it a 50K psi cartridge because my reloading book does not list ONE , repeat ONE load that goes over 50K. Now, I know that there are people with a testicle to gray matter weight ratio that would run 70K if their gun did not fly apart and claim it was great. AND, there are people here that don't know beans and would take whatever said as gospel and pour a cup full of powder in and head for the range. I am NOT going to promote loads that I do not know to be pretty much idiot proof, not edgy or pushing the envelope. That is for experts and people with lots of technical experience, as well as equipment. I know that in a handi or encore you can jack things up over a revolver, but personally, if I need more power I will get a bigger gun, not try to hotrod a smaller cartridge.
I agree whole heartedly on the bullet size, I had problems with my initial cases and a 501 sizing die. It was actually close to 502, I ordered a 500 RCBS lube/sizer die that WAS 500 or a tiny bit less and it made all the difference. In the Starline brass, the Lee push through sizer was fine, but in the Magtech brass, I had to use the RCBS.