I highlight the above response because it's an illustration of just how screwy things are here, and many other cities / states. The 'law enforcement' folks don't know the law. But by golly they'll enforce their wrongful lore about it upon you. I've had it done to me twice ('93 and '03) and beat both allegations / indictments in court.
The letter of the law(s) in CA:
All weapons must be unloaded. A loaded magazine inserted into a mag-fed weapon, no round in the chamber has been repeatedly determined to be a 'loaded' weapon in court cases.
That includes shotgun shells in a carrier attached to the shotgun. Strip them off and out.
There is NOTHING in CA law requiring separate storage of loaded mags from the weapon they are for. Yet CA law enforcement treats them in the same place as a crime and will cite and confiscate and it's up to you to beat the charges.
HANDGUNS and some semi-auto rifles classified as 'assault weapons' by the '89 and '91 CA ban attempts must be in a "locked container".
"Locked container" is NOT defined in CA law. But what it ISN'T has been declared to be a locking glove compartment or center console. Those locations are expressly forbidden by statute law.
A car with a folding back seat that allows you to reach into the trunk negates the trunk. A camper shell with a pass-thru opening or opening window into the vehicle's passenger compartment likewise negates the shell area.
There is no CA law requiring ammunition to be locked up.
Be sure to only carry magazines that hold 10rds or less. There are grandfathered exemptions to this if you were resident in and possessed higher capacity magazines in CA prior to Jan 1, 2000. But you'll be presumed guilty and have to prove that those (usually) unmarked mags met that date.
Be aware that many brands / models of AK- and AR- rifles, both whole and receivers only have been named as 'assault rifles', while many more variants have not. Know which is which and what you have and expect to be hassled and denied any opportunity to explain it to the officer in the field. most law enforcement in CA are not 'gun people', in fact departments like LAPD and SFPD actively screen such out from their recruits. So most won't know or recognize what they are looking at, even if you carry a copy of the statutes and court decisions with you. They'll just take your stuff and cite you and you'll have to fight it in court.
While there is an 'Approved Handgun Roster' in CA, it only pertains to the sale and purchase of new handguns by CA residents. You can freely bring handguns not on the roster into and thru the state with you. CAUTION - see the list of firearms specifically banned in 89-91 and the 'evil features list' to make sure your weapon choice doesn't run afoul of our 'assault weapons ban'. typically that means no pistols where the magazine is not in the grip.
There are Federal 'Free Passage' laws stating that a citizen can travel thru a restrictive zone unmolested, providing the firearm is legal where it came from adn legal where it's going. Tell that to the guys in NY State prison for getting stopped while driving thru their state. One guy was flying from appalachia somewhere into Maine for a hunt and his plane was forced to divert to La Guardia due to weather. He's in jail for bringing an unregistered firearm into NY.
CA and Fed law recognize an RV, travel trailer, tent and immediate campsite - and hotel room for that matter - as your domicile and recognize your right to be armed inside it. That doesn't stop cities like SanFran, Sacramento from passing onerous restrictions. CA having state pre-emption that plainly states CA cities can't pass more restrictive regulations than the State holds doesn't stop them either. You'll get to be a test case.
Bring it, keep it locked up and tucked away. Don't volunteer its presence during a traffic violation stop. There is no duty to inform in CA.
ADVICE section
VOLUNTEER NOTHING. Ask the reason you were pulled over, make them say it. If asked about weapons and you feel compelled to answer honestly, do so by stating you 'have a CA legal [firearm x], unloaded and stored in a locked container in full compliance with CA statutes'. That's your last opportunity to forestall an unreasonable search by a mostly honest officer. it won't stop an officer intent on jamming you up for something / anything.
DO put everything in a locked container, preferably well out of reach from the driver's seat. This is due to 'terry stop' searches, case law that make it possible to search the area a driver can reach while seated. They'll use some pretext like 'I smell weed / alcohol', something that can't be proven or fought on the spot. Better they don't find the locked container at all. Put it in the trunk. Put it the back corner of your SUV under a pile of luggage. Put it in a locked storage drawer that can't even be noticed without a full vehicle search.
DO REFUSE any half-witted ploys to allow a fishing expedition in your vehicle. Refuse permission clearly. Under all circumstances. IF their threat to make you sit and wait for a drug-sniffing dog etc, be aware that there is case law limiting the time they can reasonably detain you, especially without a solid pretext. It will be cold comfort while you are screwed with and have your vehicle tossed on the side of the road, but it may help you in court later. The officers must be able to give their reasons for such treatment to the court.
ADVICE - if you are from out of state, peel the gun stickers off your vehicle. Avoid the question. If asked to state your business, answer with something innocuous like 'family trip to WallyWorld'.
GunVault makes the MiniVault, a sheetmetal clamshell lockable container that comes with a steel security cable to look thru a vehicle seat frame or cargo tiedown point, it's large enough for even most full frame pistols and most snubby and some 4" revolvers. It can be usually found for <$30.
Otherwise, get a hard case and put some locks on it. If they pulled you over for a burned out taillight and your stuff is locked way in the back they have NO LEGITIMATE CAUSE to finger your weapons or even run their serial numbers. Although most police here demand to do that in practice. It's been repeatedly ruled against in our courts, after the fact. 'illegal search'
IF your stuff is taken, get a receipt if you can and start your case prep immediately. most jurisdictions in CA will drag their feet and obstruct any attempt to retrieve your weapons, even after a judge clears your case. And at the 1 year mark, their evidence locker will put them in the grinder / smelter. You have to go to the CA DOJ Firearms division and fill out their form to receive a demand letter from the CA AG / DOJ ORDERING the police authority to render unto Caesar.
And the 1st Offense with a concealed firearm in CA is a Misdemeanor. Judge the balance of risks for yourselves.
This is an excellent series of books, there are versions for most states.
http://www.amazon.com/How-Own-Gun-Stay-Jail/dp/0964286459
This is also a particularly useful book to have about CA gun laws.
http://www.amazon.com/California-Gu..._sbs_14_1?ie=UTF8&refRID=0SSVSA3MBGQ0C4SKNQTN
Calguns.net is moderately useful and has some good reference material / diagrams on the ins and outs of CA's burdensome and bysantine anti-firearms laws & legislation.
And if you have any particular questions, feel free to PM me.
