Not required to obtain a firearm from out of State.
That's not what I'm saying. The complication is that he's not moving to the state since he already lives here nor is he "sojourning" to the state. He doesn't need a PtA from Louisiana and sounds like he doesn't need much. The OP is asking if he'll get in trouble with HPD since he's circumventing the waiting period requirement by traveling to another state, purchasing the firearm, and bring it back with him. If he already has the PtA (and subsequently rapback), then he's not taking advantage of a loophole.
"Out of state registrants need to take firearm(s), in person, to the Main Police Station Firearms Unit no later than 5 calendar days from arrival. Out of state registrants are encouraged to arrive at the Firearms Unit no later than 3:00 pm. The out of state registration process can be lengthy. If there is a line, we may not be able to accommodate you. There is no 14-day waiting period for Out-of-State Registration. You need the following when you register your firearm:
Rapback fee $42.00. Cash / exact change or Credit Card.
Valid photo identification
The firearm for inspection (In a gun case, unloaded)
If you were born outside the United States, bring proof of citizenship such as an Original US Passport, Original Naturalization Certificate, Original Born Abroad Certificate, or if you are in the military your Enlisted (ERB) or Officer (ORB) Record Brief will suffice only if the document states you are a United States Citizen."