[rsj_hn]

> In the entire country, you must apply to the DOJ for a serial number before completion of the firearm

This is incorrect and is itself "bad advice". You do not need a serial number from the DOJ if you are not selling. But as has been stated in the comments, CA does have more stringent local rules and I'll update my comment to reflect that. I also added a link that explains the situation.

[cjhveal]

You're correct on the facts here as they relate to federal law-- I was reacting to the post's previous mention that firearm manufacture for personal use was 100% unregulated by any existing law. You've since edited it to be much more accurate and my comment isn't necessary.