Lets start over: how do you design a GPC?

[woohoo]

I don't see how it is rocket-surgery, you make a long pill with good aerodynamics, shove it hard, and you are made in the shade. Only way to get that work done is with a short fat case within the constraints of the lowers we have. I just don't see how there is more than one way to do it.

More than one way, at some point there will be a new platform because existing platforms aren't strong enough or big enough for larger cases that a true GPC will need . A green high BC bullet may be the toughest problem to solve. Could be less BC, more speed, longer smaller dia case with longer action length or longer same dia case with longer action length.
Less weight and recoil than the 308 but beat the 308s exterior ballistics with military LIKE projectiles.