Not too long ago MPPL circulated an opinion from a Hawaii Deputy AG who basically said that magazines exceeding 10 rounds were illegal. His interpretation of the law was consistent with what Funtimes has said in that ANY magazine CAPABLE of being used in a pistol cannot exceed 10 rounds. Additionally, I know of at least two instances that occured at KHSC where a LEO asked about the capacity of a rifle magazine, indicating that it could not exceed 10 rounds (rifle was an AR platform).
Here's a little mental exercise: Look at HRS 134-59 regarding butterfly knives. They are illegal and the wording of the statue is very clear on that point, offering no real room for debate such as is occuring regarding magazine capacity. Now, knowing that butterfly knives are expressly illegal, ask yourself if you have seen them for sale at any location in Hawaii. Most likely you'll say yes, but if not, I can assure you that they are for sale at various locations. So, how are they being sold if they are illegal? So, how can larger capaciy magazines be sold if they are illegal?
As for the definition of "pistol" Funtimes is entirely correct. If you doubt that, then as previously suggested, take your >10 round magazine down to HPD inserted into your firearm with a barrel less than 16 inches, and see what happens..........let us know what happens.
I think most would agree, it's a stupid law, but it is the law.