QuickLoad - Pmax question

[Nomad47]

I was thinking that the default Pmax in QuickLoad for the 6-284 was a little low, so I got to checking and here is what I found.
Default Pmax for .284 is 63,817 psi
Default Pmax for 6.5-284 is 59,465 psi
Default Pmax for 6-284 is 59,465 psi
Default Pmax for .30/284 is 55,114 psi
I would think all wildcats would be the same as the parent case. But apparently not.
Does anybody have an explanation?

 

[normmatzen]

You also see a wild disparity between 6BR, 6BRX and 6DASHER!