imported post
I respectfully suggest that you read the law as it is written:
2C:39-5 - Unlawful Possession of Weapons
b. Any person who knowingly has in his possession any handgun [...] without first having obtained a permit to carry the same [...] is guilty of a crime
Therefore, if you have a permit to carry, you may possess a handgun. Nothing is said about concealed vs. open, so by law, open carry with a permit is legal.
And with respect to long guns:
c. Any person who knowingly has in his possession any rifle or shotgun without having first obtained a firearms perchaser identification card [...] is guilty of a crime of the third degree.
Therefore, possession of a long gun (as long as it's unloaded - see section d) is legal if the possessor has an FID card. Now, if you didn't have an FID, then you're only legal if operating under the exemptions of 2C:39-6e of -6f, and transporting under the requirements of 2C:39-6g, which does NOT require a locked case. Again, quoting from the actual law:
g. All weapons being transported under [various paragraphs of 2C:39-6] shall be carried unloaded and contained in a closed and fastened case, gunbox, securely tied package, or locked in the trunk of the automobile.
Closed and fastened case is not a locked case. Also note that nothing is said about ammunition, other than the firearms must be unloaded.
What you could be confused with is the FAQ on the NJSP site that talks about transporting firearms INTO the state. In that FAQ, they're referring to the federal tansportation laws (part of FOPA), which specify a locked case (or locked in trunk), and ammunition separate. FOPA isn't applicable to intra-state transportation - NJ Statute 2C:39 is the only applicable law in that instance.