Z3RO
Here are the Federal laws/rules for Interstate transport:
18 USC § 926A - Interstate transportation of firearms
US Code (Current through Pub. L. 113-21. See Public Laws for the current Congress.)
Notwithstanding any other provision of any law or any rule or regulation of a State or any political subdivision thereof, any person who is not otherwise prohibited by this chapter from transporting, shipping, or receiving a firearm shall be entitled to transport a firearm for any lawful purpose from any place where he may lawfully possess and carry such firearm to any other place where he may lawfully possess and carry such firearm if, during such transportation the firearm is unloaded, and neither the firearm nor any ammunition being transported is readily accessible or is directly accessible from the passenger compartment of such transporting vehicle: Provided, That in the case of a vehicle without a compartment separate from the driver’s compartment the firearm or ammunition shall be contained in a locked container other than the glove compartment or console.
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Let it be clearly understood that the above law(s) apply specifically to Interstate transportation. [Nebraska to Iowa, for example.]
Now...How about State laws?
Generally, they can't be tougher than Federal law. As it happens, most states do follow Federal law. Except some states pay little or no attention to Federal law. Like Illinois, for example. Illinois does what it damn well pleases. You can get a lawyer. You are allowed to call your lawyer from jail. You pay all fees, fines, legal expenses, court costs, etc. And the phone call, of course.
To be sure in the case of in-state travel, read the laws for each state through which you plan to travel. Don't travel through Illinois without a FOID. [You can look it up.]
Now, there are many situations that you can think up which do not exactly fit the above Federal law circumstances. Grey areas. Best to strictly lean toward the Very Letter of the Law.
So that you don't lose (a) your money, (b) your guns, and (c) your time.