.50 BMG rifles
With 2004's AB 50, California classified .50 caliber BMG rifles - and ONLY that precise caliber - as a new kind of 'assault weapon'.
There are no special restrictions on .50 caliber BMG ammunition, and there are no special restrictions on other variants of .50 caliber rifles or ammunition.
The justification in Penal Code 30505 (old 12275.5), such as it is, reads
(b) The Legislature hereby finds and declares that the proliferation and use of .50 BMG rifles poses a clear and present terrorist threat to the health, safety, and security of all residents of, and visitors to, this state, based upon findings that thosefirearms have such a high capacity for long distance and highly destructive firepower that they pose an unacceptable risk to the death and serious injury of human beings, destruction or serious damage of vital public and private buildings, civilian, police and military vehicles, power generation and transmission facilities, petrochemical production and storage facilities, and transportation infrastructure. It is the intent of the Legislature in enacting this chapter to place restrictions on the use of these rifles and to establish a registration and permit procedure for their lawful sale and possession.
The restricted weapons are legislatively defined as Penal Code 30525 (old 12275.5)
As used in this part, ".50 BMG cartridge" means a cartridge that is designed and intended to be fired from a center fire rifle and that meets all of the following criteria: (a) It has an overall length of 5.54 inches from the base to the tip of the bullet. (b) The bullet diameter for the cartridge is from .510 to, and including, .511 inch. (c) The case base diameter for the cartridge is from .800 inch to, and including, .804 inch. (d) The cartridge case length is 3.91 inches.
(a) As used in this part, ".50 BMG rifle" means a center fire rifle that can fire a .50 BMG cartridge and is not already an assault weapon or a machinegun. (b) A ".50 BMG rifle" does not include any antique firearm, nor any curio or relic as defined in Section 478.11 of Title 27 of the Code of Federal Regulations.
Note carefully that this is ANY centerfire .50 BMG rifle - this is not restricted to semi-automatic weapons as the other 'assault weapon' definition is.
.50 BMG rifles were added to various places in the 'assault weapon' sections: Penal Code 30600 (old 12280)
(a) Any person who, within this state, manufactures or causes to be manufactured, distributes, transports, or imports into the state, keeps for sale, or offers or exposes for sale, or who gives or lends any assault weapon or any .50 BMG rifle, except as provided by this chapter, is guilty of a felony, and upon conviction shall be punished by imprisonment in the state prison for four, six, or eight years. (b) In addition and consecutive to the punishment imposed under subdivision (a), any person who transfers, lends, sells, or gives any assault weapon or any .50 BMG rifle to a minor in violation of subdivision (a) shall receive an enhancement of one year. (c) Except in the case of a first violation involving not more than two firearms as provided in Sections 30605 and 30610, for purposes of this article, if more than one assault weapon or .50 BMG rifle is involved in any violation of this article, there shall be a distinct and separate offense for each.
Penal Code 30610 (old 12280) continues, to specify the punishment and that there would be a registration period:
(a) Any person who, within this state, possesses any .50 BMG rifle, except as provided in this chapter, shall be punished by a fine of one thousand dollars ($1,000), imprisonment in a county jail for a period not to exceed one year, or by both that fine and imprisonment.
The registration period has expired: Penal Code 30905 (old 12285)
(a) Except as provided in Section 30600, any person who lawfully possesses any .50 BMG rifle prior to January 1, 2005, that is not specified as an assault weapon under former Section 12276, as it reads in Section 19 of Chapter 606 of the Statutes of 1993, or former Section 12276.5, as it reads in Section 3 of Chapter 954 of the Statutes of 1991, or defined as an assault weapon pursuant to former Section 12276.1, as it reads in Section 3 of Chapter 911 of the Statutes of 2002, shall register the .50 BMG rifle with the department no later than April 30, 2006, pursuant to those procedures that the department may establish.
Transfer in CA is extremely limited, parallel to 'assault weapons': Penal Code 30930
Except as provided in Section 30940, no .50 BMG rifle possessed pursuant to this article may be sold or transferred on or after January 1, 2005, to anyone within this state other than to a licensed gun dealer or as provided in Section 31100.
And .50 BMG rifles are subjected to the same transport and places of use restrictions applied to 'assault weapons' in Penal Code 30945 (old 12285):
Unless a permit allowing additional uses is first obtained under Section 31000, a person who has registered an assault weapon or registered a .50 BMG rifle under this article may possess it only under any of the following conditions: