The .50 Caliber BMG Regulation Act of 2004 is a law in the state of California that effectively banned all .50 BMG-caliber rifles from being sold in the state. The law took effect on January 1, 2005. Background The legislature of California declared that "proliferation and use" of .50 BMG rifles posed a terrorist threat, as well as a threat to the "health, safety, and security of all residents" of California. The act required existing .50 BMG rifles to be registered with the state and prohibited the sale of any rifle after the ban went into effect. To quote the state web site, the act "regulates the .50 BMG rifles in essentially the same manner as assault weapons." The law specifically allowed a registration period of one year, now passed, to register any such firearms, after which unregistered weapons would become illegal firearms. Definitions "A .50 BMG rifle is defined as a centerfire rifle that can fire a .50 BMG cartridge and is not already an assault weapon ... or a machinegun" ".50 BMG cartridge" is defined as a cartridge that is designed and intended to be fired from a centerfire rifle and that meets all of the following criteria: (1) It has an overall length of from the base to the tip of the bullet. (2) The bullet diameter for the cartridge is from .510 to, and including, . (3) The case base diameter for the cartridge is from to, and including, .804 inch. (4) The cartridge case length is . (PC § 12278.) Exceptions/Exclusions to California Penal Code 30905, et al. The law does not apply to the law enforcement officers with permission from their employing agencies. Exceptions are granted to rifles classified as antiques or Curio and Relics as defined by the BATFE. Out-of-state owners may bring .50 BMG rifles into the state for shooting competitions. Limited exceptions are granted for exhibitions, displays, and education projects sponsored by law enforcement or government agencies. You hold a valid permit to possess an assault weapon specifically (not just a general concealed carry permit) from the State Department of Justice. You lawfully possessed the rifle before it was made illegal (i.e., before January 1, 2005) and registered it before April 30, 2006 with the State Department of Justice. You are the executor or administrator of an estate that lawfully holds such firearms. Controversy As a result of the ban, the