I suspect that there are some places in this country where you will be illegal no matter what you do. In order to keep these occasions to a minimum, the more inaccessble the weapon, the safer you are. So optimal transport would be disassembled and locked in a safe not available from the inside of the vehicle, with the ammunition in a separate locked container.
Unloaded and in a locked container not accessable to the driver may be more conveniant, and only add a few more places where you would be illegal.
At one time, there was a federal law which stated that if you were travelling from a place where you could legally possess a gun to another place where you could legally possess a gun, you could not be arrested for possession during the trip. Don't know if this law is still in effect, or the requirements to be protected under this. Still would probably be unpleasant.
Of course disassembled and scattered about kinda defeats the purpose of that type of weapon. The gray areas are one of the big problems with concealed carry laws. Conceal it. Don't do anything to invite the police into your RV and you got it whipped.
Krazee gave you some good advice. Dont let any police into your unit with out a warrant and dont post any stickers like NRA or Protected by Smith & Wesson, etc as that can cause problems. I try to stay out of some of the states with these pro criminal, anti citizen laws like NJ, NY, MA, etc. If I have to go thru them I spend a minimum amount of time and money.
I agree with what janlarmil said....don't let them in your unit without a search warrant. Not sure about other states, but in Arkansas, your motorized coach, class A, class B, or class C is considered your home and they CANNOT enter unless you authorize them or they have a search warrant....not sure about a 5th wheel or travel trailer. Just don't invite them by placing stickers on your unit as janlarmil has suggested and you should be fine.
When traveling with firearms in your RV--I suggest you get a copy of a book entitled "Traveler's guide to the firearms laws of the fifty states" (19.95)--It list most of what you need to know about this.. There is a federal law that is supposed to pre-empt local (state) law regarding firearms carry within your vehicle (McClure-Volkmer)Also, Realize that an RV that is moving is a VEHICLE.. An RV that is stationary, and connected up to "shore" facilities could be argued to be a residence.Do not count on this though..Also, realize that local "town" ordinances might put you in jail, with your weapons confiscated, federal law notwithstanding.. I would not allow a search without warrant, or advertise the fact you are carrying..Also, some jurisdictions consider a weapon "loaded" even with the ammo separated, (if it is in the same vehicle)..Some states consider self-loading "Military pattern" rifles to be "assault weapons" whether they are or not.. Be in the know!!
I found the book in an ad in back of "American Rifleman" but Amazon should list it, mine is 2003, the 2004 copy is out now..It lists all the states, and gives a quick rundown of the state's laws. Also, gives some "horror stories" about a guy who had a Concealed carry permit, and figured he was covered. (you probably aren't)--Cheap insurance..I have a class 03 FFL curio and relic collector, and was worried about moving up North from FL- It turns out, I wouldn't drive through CT,MA,NJ,MD, and a few others regardless..Nasty way to get to N.H. but, maybe I'll stay in Vermont, (no license necessary) to carry.
But, remember the McClure-Volkmer Firearms act which went through about the same time as the Clinton gun ban, is supposed to pre-empt local laws/ordinances, but some states have conflicting laws within the same state, due to local ordinances.. Take Care--