Say if I go to a state where handgun mags can hold 10+. Could I buy magazines up there and before I fly back here I put a blocker (rod binded to spring that blocks follower from going down past 10 rounds, and epoxy the basepad) to make it permanent?

Might be a common suggestion here and this us my response
“Buy the factory 10 rounders”, those are short magazines 126mm and I like 140mm length for competition here and in general.

I have extra magazine rod blockers, i can buy epoxy so i wont have to pay a FFL/ gun store.

Say if I go to a state where handgun mags can hold 10+. Could I buy magazines up there and before I fly back here I put a blocker (rod binded to spring that blocks follower from going down past 10 rounds, and epoxy the basepad) to make it permanent?

Might be a common suggestion here and this us my response
“Buy the factory 10 rounders”, those are short magazines 126mm and I like 140mm length for competition here and in general.

I have extra magazine rod blockers, i can buy epoxy so i wont have to pay a FFL/ gun store.

Pistol magazines that were made to hold >10 rounds are legal if they are blocked to only hold 10 rds.  So, yes, they are legal to bring back.

When you start asking about detailed procedures for blocking, it's best to talk to a LGS / gunsmith to see how they block mags to make them legal here.

I've seen articles on making mags legal for CA, and they take a roll pin made for a gas block, cut it in half, and insert it into a drilled hole to keep the base plate from being removed without tools and extra effort.  Here, however, permanent epoxy on the base plate is the norm. 

Epoxy seems like overkill to me.  IMO

The HRS 134-8 section says:

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.

The plain English definition of "readily" includes "easily' and "quickly."  Nothing in the statute requires permanent affixing of the base plate.  Doing that prevents parts replacement and routine maintenance.

So, you can choose the 'just to be safe" path and use epoxy.  Or, you can use the "common sense" path and just make the base plate difficult and time-consuming to remove.

i don't think I've ever seen/read where anyone here was charged for having improperly blocked mags.  However, if HPD ever gets their hands on them, they will probably confiscate any they deem inadequate based on their own interpretation of the law.

As usual, if you're looking for a definitive answer, your best option is to consult an attorney.

I've had mags blocked through LGS and variety of ways.  For polymer mags, a blocker in the follower, typically with epoxy.  That said, the epoxy has varying degress of "not readily restored".  Not sure if was the epoxy or the work to install, but some fell off before too long.  Of course, I made sure to make it "not readily restored" again. . .

For metal mags, they typically made a dimple that allowed only 10 rounds. 

For competition, I have some mags with extended baseplates.  Yeah, better to have standard cap mags though. . . When traveling for competition or classes to free(er) states, standard cap mags are essential.  Otherwise you're jamming mags way to often. 

I've had mags blocked through LGS and variety of ways.  For polymer mags, a blocker in the follower, typically with epoxy.  That said, the epoxy has varying degress of "not readily restored".  Not sure if was the epoxy or the work to install, but some fell off before too long.  Of course, I made sure to make it "not readily restored" again. . .

For metal mags, they typically made a dimple that allowed only 10 rounds. 

For competition, I have some mags with extended baseplates.  Yeah, better to have standard cap mags though. . . When traveling for competition or classes to free(er) states, standard cap mags are essential.  Otherwise you're jamming mags way to often.

I had to deal with that at Front Sight.  I was the odd man in my group without a shooting partner, so I got to shoot each exercise twice.   

The problem was, having only 10 rds per mag, I was reloading like a Tasmanian Devil!  I had to sit out one or two volleys because I was still trying to reload.

Great practice -- at reloading magazines in record time!  My hands were sore, too, in spite of using a speed loader.

 

I use these for Sigs

https://www.magazineblocks.com/magento/products/magblock-kits.html?limit=all

I’ve been using a 9mm speed loader from this brand for a while, and it cut my reload time way down without wrecking my thumbs. What surprised me most was how easily it worked across my different mags, so I didn’t need a bunch of separate tools. The bundle deal helped me grab an extra one to keep in my range bag.

I’d stick to buying mags that are already permanently limited to 10 rounds. DIY blocks might not count if they’re removable, and you don’t want to risk it under Hawaii law.

I use these for Sigs

https://www.magazineblocks.com/magento/products/magblock-kits.html?limit=all

And teachers used to say I read slow!