The 48 hour requirement is for notification of private sales. If you sell a rifle or shotgun to a private party, you as the seller have 48 hours to notify HPD that you have transferred the firearm. The 5 day requirement for registration is for the buyer. As usual, the people at the counter rarely know the laws and regulations that they are required to know.
HRS 134-2:
In all cases where a rifle or shotgun is acquired from another person within the State, the person who is transferring title to the rifle or shotgun shall submit, within forty-eight hours after transferring the firearm, to the authority which issued the permit to acquire, the following information, in writing: name of the person who transferred the firearm, name of the person to whom the title to the firearm was transferred; names of the manufacturer and importer; model; type of action; caliber or gauge; and serial number as applicable.http://www.capitol.hawaii.gov/hrscurrent/Vol03_Ch0121-0200D/HRS0134/HRS_0134-0002.htmHonolulu PD website:
For
in state registration, take your firearm in person to the Main Police Station Firearms Section
no later than 5 calendar days from a purchase or acquisition for registration. You need the following when you register your firearm:
Valid photo identification
Your original firearms permit
Name, address, phone number of seller, in state registration only
The firearm for inspection
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.
Out of state registrants need to take firearm(s), in person, to the Main Police Station Firearms Section
no later than 3 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:
http://www.honolulupd.org/information/index.php?page=gunmain#tabs-3