Does 65G + EPR = GPC ?

[A5BLASTER]

I would put my thinking in a bullet say 100 grain made with the specs of one of the new cavity back bullets, think it would be short enough and hold enough weight and with the cavity in the back of the boat tail it would allow more powder in the case increasing MV in the shorter barrels the military use's.

I could be way off but that is my idea, what you think stanc.