Ok, here we go... DO NOT BLAME ME IF YOU GET ARRESTED. I am not a lawyer, I am merely relaying text of the law.
After calling the California DOJ firearm law information line, I talked to an employee who walked me through the laws pertaining to "importation" of assault weapons by non-residents into California for a temporary purpose, such as a sanctioned competition..
California Penal Code section 30665 says :
ARTICLE 2. Unlawful Acts Relating to Assault Weapons and .50 BMG Rifles [30600 - 30680]
( Article 2 added by Stats. 2010, Ch. 711, Sec. 6. )
CA PC 30600 says no you can't do it without an exemption...... 30665 details the exemption for non-residents who want to bring their AW into Cali for a specific purpose, like a sanctioned competition... reas below: YOU HAVE TO MEET ALL THE FOLLOWING CRITERIA BELOW.
30665.
Sections 30600, 30605, and 30610 shall not apply to the possession and importation of an assault weapon or a .50 BMG rifle into this state by a nonresident if all of the following conditions are met:
(a) The person is attending or going directly to or coming directly from an organized competitive match or league competition that involves the use of an assault weapon or a .50 BMG rifle.
(b) The competition or match is conducted on the premises of one of the following:
(1) A target range that holds a regulatory or business license for the purpose of practicing shooting at that target range.
(2) A target range of a public or private club or organization that is organized for the purpose of practicing shooting at targets.
(c) The match or competition is sponsored by, conducted under the auspices of, or approved by, a law enforcement agency or a nationally or state recognized entity that fosters proficiency in, or promotes education about, firearms.
(d) The assault weapon or .50 BMG rifle is transported in accordance with Section 25610 or Article 3 (commencing with Section 25505) of Chapter 2 of Division 5.
(e) The person is 18 years of age or over and is not in a class of persons prohibited from possessing firearms by virtue of Chapter 2 (commencing with Section 29800) or Chapter 3 (commencing with Section 29900) of Division 9 of this code or Section 8100 or 8103 of the Welfare and Institutions Code.
(Added by Stats. 2010, Ch. 711, Sec. 6. (SB 1080) Effective January 1, 2011. Operative January 1, 2012, by Sec. 10 of Ch. 711.)
I asked "what about training class that's not necessarily directly connected to a competition"
They advised its not part of the exemption. But it can be a "gray area." As it pertains to being exempt. They went on to say it would basically be up to the prosecutor to decide to file a charge, and ultimately the jury to determine if a person is guilty of unlawfully importing an assault weapon into California... a FELONY.
So.... If I was you... I wouldn't do it. If I were to pull you over, discover the "assault rifle" , and you provided me your enrollment in a training class and the text of the law as stated above, I personally would let you go because I have a brain. But, there are lots of cops that don't give a shit and if they see and gun violation, they do whatever the law says.