Might not be a bad idea to keep a copy of the relevant statute with you. Many LEOs' knowledge of firearms laws is, to put it charitably, questionable.
Here's something that happened to me not long ago. I'm reluctant to tell it, because it's somewhat embarassing, but here goes.
My wife, daughter and I were in Maryland visiting my folks - staying at a hotel in Timonium. We checked out and headed for Delaware for a side trip. About thirty minutes into our drive, we looked at each other, and simultaneously realized that neither of us had remembered to pack up the pistol - it was still in the nightstand of the hotel room along with the spare mags. Each of us thought the other had packed it up (of course that was not the case).
Anyway, I immediately called the hotel, notified them of the situation and asked them to leave the room alone and that I was on my way and would go up to the room and recover the pistol. Whoever I spoke with agreed and we arrived shortly afterward.
When we got to the hotel, we were met by the hotel manager, the security manager, and the front desk manager, who informed me that...oops...change of plans, sir. They had called the Baltimore County sheriff's office and a deputy was on his way.
Now, it's not illegal to accidentally leave a firearm in a hotel room, but it's certainly embarassing. My family and I cooled our heels waiting for the LEO to arrive, which he did about an hour later. When he arrived, he of course took my ID and asked if I had a permit. ***? You don't need a permit to possess a firearm in a hotel room, and I told him so, but also provided him with my Texas CHL (which has no legal standing in Maryland, btw).
The cop asks to be taken to the room, so up we all go. The hotel manager, front desk manager, and security manager, and I all wait outside while the LEO enters the room and does, well...God only knows what. We were standing outside the room for nearly an hour, after which he opened the door and called me inside.
He told me, and I'm not kidding, that I was lucky I had a permit or otherwise he would have taken me to the police station (charges, officer? What might they be?). He then told me to retrieve the pistol and mags and leave the hotel.
Well, I proceeded to the bed where he had laid the pistol, and removed the magazine and the round from the chamber, and shucked all the rounds out of all the magazines. I then proceeded to lock the pistol in the case (unloaded, of course), and the mags and loose shells in a separate bag. The cop looked at me as though I had watermelons dropping out of my sphincter, then asked me what I was doing?
I told him that I was doing what I needed to comply with federal and state laws regarding the transportation of firearms, and he told me that that wasn't necessary if I had a permit. Again, ***? What do they teach these guys?