I'm breaking some CA gun law if I do this, right?

[PEBKAC]

if you were to turn a pistol to a rifle. wouldn't you need to have it inspected and "ok'd" before being able to have it? like re-dros?

No...why would you think you would need to do this?

[hcbr]

you're just going to have to get another lower and registered it as a pistol lower

[zombiescanlearn]

Not only state laws are broken, but federal laws as well. SBR is an NFA item.

And I was only worried about CA laws. My parents always said I was an overachiever. Ok, back to the drawing board.

[brando]

Federal Law = Lame. That's your answer.

There, I fixed it for you.

[SigEquinox]

Question: if you have one pistol lower but more than 1 <16" upper, do you have to worry about constructive possession?

[Rebellious]

I was planning to purchase a HK 10.4" upper receiver and put it on my lower receiver. Am I breaking some CA law or is that fine?

I'm surprised nobody said this so far......Where are you planning on purchasing this? Everywhere I have checked has been backordered for a long time. Please feel free to share. And to your question, if you are putting it on a registered rifle lower then it's a BIG NO! If you are putting it on a pistol lower your Good To Go!