I've spent a while reading through the topics on here about ensuring legal compliance with the pistol rules (Thanks dogman for all the great posts), and I wanted to make sure I'm not missing anything at this point before I start the build. I also figured I'd try to consolidate and create a short, succinct post to have it in one place.

The two options I see are welded magazine or bolt action.

- Get the lower, register as a pistol (or other, I suppose)
- Kali Key installed in the upper creating a bolt action vice semi-automatic
- No mags over 10 rounds
 

Am I missing anything?

I've spent a while reading through the topics on here about ensuring legal compliance with the pistol rules (Thanks dogman for all the great posts), and I wanted to make sure I'm not missing anything at this point before I start the build. I also figured I'd try to consolidate and create a short, succinct post to have it in one place.

The two options I see are welded magazine or bolt action.

- Get the lower, register as a pistol (or other, I suppose)
- Kali Key installed in the upper creating a bolt action vice semi-automatic
- No mags over 10 rounds
 

Am I missing anything?

You may have to educate HPD on the Kali Key and be prepared for them to reject it. 

The Kali Key leaves the gas system intact.  Swapping out the BCG and reinstalling your charging handle reverts the firearm back to a semi-auto without tools or hassle.

Not every California compliant AR-15 add-on product is acceptable here.  e.g. The bullet button.  The reason is CA laws have more detailed wording than ours do, which gives innovators some wiggle room to come up with options that meet the letter of the law.  HI is more like, "it can't have a semi-auto action."  The wording is ambiguous, which seems to allow HPD to define what they will and won't accept.

Side note:  The Kali Key only works for direct impingement (DI) gas systems, not piston systems.

I've spent a while reading through the topics on here about ensuring legal compliance with the pistol rules (Thanks dogman for all the great posts), and I wanted to make sure I'm not missing anything at this point before I start the build. I also figured I'd try to consolidate and create a short, succinct post to have it in one place.

The two options I see are welded magazine or bolt action.

- Get the lower, register as a pistol (or other, I suppose)
- Kali Key installed in the upper creating a bolt action vice semi-automatic
- No mags over 10 rounds
 

Am I missing anything?

You could look into the lever action AR guns though I don't know if you can buy the lower by itself as a pistol.
The other option is a pump action AR-15. They do make some in rifle length but I have never seen the lower for sale by itself.
I  did have a design for a pump handle to make a pump AR-15 but I never got to the step to design a rod to connect the handle to the bolt. I wanted to build a pump AR pistol in .300 blackout but too busy to go down that road.