Even in states that restrict all gun purchases to those over the age of 21, legal adults under the purchase age can still own firearms. They can't buy them, but if someone gifts them one, they can maintain ownership. They can receive one via inheritance, as well.

There are ways for them to lawfully own guns.

Yet in Hawaii, there are issues. 

You see, it's now going to be illegal for those lawful gun owners to buy ammunition with which to actually use the guns they lawfully own.

The measure, SB 2845 zipped through the Democrat-controlled state legislature with only a handful of lawmakers voting in opposition. This sent the bill to [Hawaii Gov. Josh] Green's desk, a Democrat who has signed multiple anti-gun laws since taking office, often with members of gun control groups attending public signing ceremonies. 

The new law, which becomes effective immediately, not only bumps the age of purchase for ammunition to 21 and requires retailers to check the government-issued ID of purchasers to verify age, but also makes it a crime for adults under 21 to "own, possess, or control" ammunition. This means retailers and distributors could be criminally charged should they make a sale to those under 21. 

In other words, if they have a firearm at all, they can't actually operate it since somewhere along the way, they'll be in possession of ammunition.

Now, there are exceptions, and that includes taking someone hunting or to the range, so it's not as bad as it could have been, but this is still bad enough. The idea that law-abiding adults cannot be trusted with ammunition is extremely problematic, particularly since getting someone to buy ammunition on your behalf is extremely easy to do among the criminal underclass.

I mean, they can often get people to buy guns for them, and those are serialized and mostly traceable. Essentially straw-buying ammunition becomes even easier because there's no way to determine who bought a given round.

Since this requires simply a valid government-issued ID of some kind, it becomes a trivial matter entirely.

So the result is that there will be no impact to criminals at all but law-abiding citizens get well and truly screwed.

This measure went into effect immediately, which means that technically, a 20-year-old who had ammo laying around is now in violation of the law, which is yet another issue with what just happened in Hawaii.

Of course, this isn't over.

I'd be very surprised if attorneys for at least one gun rights organization aren't already at work looking at a lawsuit to try and overturn this measure. Even under the Supreme Court's Rahimi "clarification" of Bruen, I can't imagine a historic analog anywhere close to a prohibition on legal adults who have done nothing to suggest they're dangerous. 

So yeah, this is going to go to court and I can't see how a reasonable court would look at this and decide it's constitutional.

And no, a court that makes decisions based on the "aloha spirit" isn't a reasonable court. Frankly, though, I don't imagine a gun rights group would challenge this in state court after that particular fiasco.

No, let the federal courts get this and smack it down lest some other state think it's a good idea.