I'd feel pretty confident arguing that pin&welding a muzzle device onto a threaded barrel leaves you without a threaded barrel. I'm not aware of case law but it's rather accepted to do that on "featureless" builds in other states.
Per Hawaii law, the actual assault pistol criteria is:
(2) A threaded barrel capable of accepting a barrel extender, flash suppressor, forward hand grip, or silencer;
If a device is pin&welded onto the threads, it seems obvious that the barrel is no longer "capable of accepting" any of those items.
But for the sake of my question, let's assume that the threads were lathed off before a muzzle brake was welded onto the barrel. It sounds like you're of the opinion that the weight of the welded-on muzzle brake would NOT count towards the "manufactured weight" of the pistol?
It gets fun because there'd be no way of actually measuring the original weight of the pistol without taking the "permanently" affixed muzzle brake back off of the pistol.
Show me a single HRS section that includes the phrase "
unless it seems obvious...." If it's included in the statute, it's covered. If it's not in the statute, it's not part of the law.
What you're engaging in is personal analysis and drawing a conclusion based on firearm function.
What the law says is technical, and it doesn't provide exclusions based on specific implementations.
If you can find a legal precedent that mitigates the technical definition of threaded barrel as it applies to designating a firearm "assault weapon/pistol" by permanently installing something over the threads, then I'd say you have a case. Otherwise, it's an opinion based on reality -- not the actual law.
Is the barrel threaded? Yes.
Does it accept a barrel extension? Yes. (One is already attached and it is pinned & welded)
Does the extension being pinned & welded constitute an exclusion to the threaded barrel rule? Maybe -- it does in your mind. but not in the law.
You're asking for an interpretation. I interpret it based on the text. I see nothing about threads having exclusions. The only exclusion I see is a permanent extension to increase the barrel length of a rifle to make it legal at 16" per the NFA.
The criteria that define an assault weapon vary from place to place. As such, the interpretations will also vary. I tend to look at it from a practical perspective, if you have a barrel and extension that you intend to pay to have permanently connected while risking an unfavorable legal interpretation of the firearm drawing a felony charge, I'd rather just install a barrel of the desired length with no threads at all. Seems like a simpler and more reliable solution than hoping the current state prosecutors know more about guns than what they learned watching John Wick.
When you say something is obvious in the law, try to remember who we have making and enforcing those laws. Not very obvious from their perspective, IMO.