Those libs are crafty devils sometimes. If they tried to attack a new caliber cartridge they try and avoid pitfalls There was too few .50 BMG owners in California to stop the .50 BMG ban they passed.
If the new cartridge you have was called for example the .12 gauge Hubel Ultra Magnum, the libs would work out a deal to attack only your cartridge by name and spare the regular 12 gauge shells from the attack. They wouldnt have the political power (yet and hopefully never will) to battle the regular 12 gauge (too established). That would be political suicide.