I'd have to side with Funtimes on this as well. It all comes down to this:
(c) The manufacture, possession, sale, barter, trade, gift, transfer, or acquisition of detachable ammunition magazines with a capacity in excess of ten rounds which are designed for or capable of use with a pistol is prohibited. This subsection shall not apply to magazines originally designed to accept more than ten rounds of ammunition which have been modified to accept no more than ten rounds and which are not capable of being readily restored to a capacity of more than ten rounds.
It's the line "capable of use" that is the nail in the coffin. AR15 platform "Assault pistols" exist. Take for example the Patriot. It meets all the qualifications of "Assult Pistol" described by the HRS
"Assault pistol" means a semiautomatic pistol which accepts a detachable magazine and which has two or more of the following characteristics:
(1) An ammunition magazine which attaches to the pistol outside of the pistol grip;
(Check) (2) A threaded barrel capable of accepting a barrel extender, flash suppressor, forward hand grip, or silencer;
(Check) (3) A shroud which is attached to or partially or completely encircles the barrel and which permits the shooter to hold the firearm with the second hand without being burned;
(Check) (4) A manufactured weight of fifty ounces or more when the pistol is unloaded;
(Check) (5) A centerfire pistol with an overall length of twelve inches or more; or
(Check) (6) It is a semiautomatic version of an automatic firearm;
(Check)Because they exist, AR 15 magazines are "capable" of fitting into those aformentioned "Assult pistols" (regardless of wether the AR15 "assult pistols" are even legal in Hawaii.)
Therefore, magazines over 10 rounds for the AR15 are illegal in Hawaii.
A little off topic, but if all of this is true how is it guys can have those .22lr MP5 looking guns? Aren't they technically "assult pistols"?