It seems (on its surface) a cartridge that needs the arm's dimensions to shine, since they seem to vary, along with the components.
I'd make the headspace fit the gun, the bullet fit the throat and groove and fit the twist.
Rocky, on the surface it really just appears to be a giant Hornet....
It would be interesting to toy with, as getting a cast bullet to its original ballistics shouldn't be a tradeoff.
