The following is heavily excerpted from the Legislative Watch column in the November 2004 issue of The Firing Line, the newsletter of the California Rifle and Pistol Association. I found the last paragraph of the section I have reproduced here hilariously funny. The discussion of the technical deficiencies in California AB50 leading up to this is cut for the sake of those who aren't interested. Comments in italics are mine.
AB50 (Koretz, D. West Hollywood), signed by the Governor, was poorly written and, as a result, will be almost completely ineffective for its stated purpose. It is another good example of firearms legislation written and enacted by people who think they know a lot about firearms, but actually know little. [...]
(AB50 sought to ban .50 BMG long-range rifles in California on the laughable grounds that they could be the preferred weapons of criminals -- where have we heard that before? -- and terrorists. Hint to the California leglslature: Terrorists have weapons FAR, FAR more effective, destructive, and harder to defend against than a .50 BMG bolt-action rifle available to them. This bill was a solution in search of a problem from the moment of its conception.)
The critical drafting error in AB50 that renders the bill ineffective, and which reveals a gross lack of knowledge by its sponsors about firearms and ammunition, can now be revealed, since it is too late to amend the bill. To correct it will take the passage of another bill next year and, if everyone gets out to vote, such a bill can be stopped long before it reaches the Governor's desk. The sponsors of the bill naively tied everything in the bill ti the military specifications for the .50 BMG cartridge. They even locked the specifications into a statute, listing each cartridge dimension in thousandths of an inch. Therefore, a cnartridge that varies even slightly from these dimensions is not a .50 BMG for purposes of the new state law, and rifles that are chambered to fire it are not subject to the provisions of AB50.
All that is necessary to change an AB50 rifle to a non-AB50 rifle is to change the chamber dimensions just enough that a .50 BMG round can no longer be chambered. This can easily be accomplished by having a gunsmith set the barrel back a small amount and then dress up the chamber with an appropriate reamer. () It is simple and relatively expensive. Since most people who have one of these rifles are also handloaders, standard .50BMG cases can be easily reformed to the new chamber dimensions. The result will be a rifle and cartridge combination that is not a .50 BMG under the state "assault weapons" law, but which is essentially the same thing ballistically.
Manufacturers are already working on designing new chamber dimensions. What the new round will be called is not yet known, but some suggestions have been the California Special, the Girlie Man Fifty (GM .50), and the .50 Koretz.
I got to that last paragraph and completely lost it. Ask cymrullewes for corroboration. Your mileage may vary depending on your feelings about firearms.