Lets start over: how do you design a GPC?

[stanc]

That's a good question. You've got my wheels turning Stanc. Let me throw this out there. What's the implications of a lead free bullet that's more steel and less copper, relative to the current common ratios? Could that move us towards the weight we're looking for?

Steel is less dense than copper, so if you make the bullet more steel, it'll move you further away from your goal of a heavy bullet.

As best I can tell, to get close to 130gr in a boat tail spitzer, it'd have to be made of solid copper. However, that type of construction wouldn't interest the US, Europe, Scandinavia, or anyone else.