They REFUSED to accept my lower and forced me to go home and bring my upper. Told me that I had 5 days to register the complete rifle and if I didn't I'd be breaking the law. They don't care about the law. The cocksucker sergeant in charge of the firearms division that morning said as much. He literally said "fuck the ATF, this is Hawaii" and refused to follow the letter of the law described in HRS 134. Fuck HPD and the small dick bullies that work for them. They can come confiscate my 30 round magazines 1 round at a time.
I wonder what he would have said if you told him you don't own an upper yet? I also wonder if this is a new policy because I have heard before people registering lowers just fine.
I went and checked the Hawaii law that defines firearms.
https://www.capitol.hawaii.gov/hrscurrent/Vol03_Ch0121-0200D/HRS0134/HRS_0134-0001.htm""Firearm" means any weapon, for which the operating force is an explosive, including but not limited to pistols, revolvers, rifles, shotguns, automatic firearms, noxious gas projectors, mortars, bombs, and cannon."
According to state law the sergeant is partially correct, they don't have to follow ATF definitions.
However the rest of what he is saying appears to be an interpretation of Hawaii's legal definition which really doesn't do enough to address the issue of what constitutes a firearm. This type of issue may force them to redefine what a firearm is because right now the law is just too vague to deal with situations like an upper and lower.
Now this is just my own interpretation but as I read the definition, it would seem the upper and lower would both be needed to become a firearm since neither by itself would operate by explosive alone.