So how can removing a bullet button from a registered assault weapon make a different unregistered assault weapon
Because that's what CA DoJ's lawyers said, and wrote into the regulation, which was passed using the legal process. Since the regulation has not been successfully challenged in court or in an administrative process, it remains in force.
But you have to understand the logic behind what it says in the regulation. Simply quoting a single sentence and taking it out of context will lead to the wrong conclusion.
To begin with, as we've been discussing for several pages in this thread (and some people are refusing to understand): there is a distinction between an AW = assault weapon (defined as something that has transportation / possession / mailing / manufacturing restrictions) and a RAW = registered assault weapon (defined as something that has a valid registration for that weapon with that make/model/serial, and perhaps in that configuration). Sometimes an AW is not a RAW (and that is usually quite illegal). Sometimes a RAW is not an AW.
The logic behind the DoJ's regulation has been well known for a long time, and we were warned about it before the DoJ opened the extra registration period for BBRAWs in about 2017. Remember, most people (at least on the usually clueless, anti-government and overly optimistic Calguns forum) thought "once registered as a RAW, I can take the bullet button off". And user Flavio kept warning us: "no, you won't be able to, read the law carefully". Well, Flavio has more brains than the "manager of lawyers" and his minions.
The logic behind that very abbreviated statement is this: To register a lower receiver under the BBRAW registration, it has to have a bullet button. Only if registered properly does it become exempt from the AW (not RAW!) restrictions against an attachable magazine (and I deliberately did not say detachable here). The registration is only valid for that weapon (make/model/serial) in that configuration. If the BB is missing, the registration could not have been performed in the first place, and is not valid. Putting the BB back on makes the registration valid again. The logic behind the (admittedly over abbreviated) statement "it is a different AW" is: the registration is only valid
IF AND WHEN the BB is in place, otherwise it is a
DIFFERENTLY CONFIGURED weapon.
They can't have it both ways.
They are not. The definition of what constitutes a weapon, an AW, a RAW, and a BBRAW are complex. The fact that for an untrained and unskilled amateur brain they seem to overlap or contradict each other doesn't change the law.
As an example, I have sitting next to me on my desk a "California Practice Guide" for an area of law I'm not familiar with, namely collections. The section on what constitutes a "homestead exemption" is about 30 pages long, and distinguishes between homestead exemption, dwelling exemption, and declared homestead exemption. And that's just for California law; if we add federal bankruptcy law (for which the manual is upstairs), it gets probably twice as complicated. And all these laws exist for good reason. Just like people joke that OSHA regulations were written in blood, laws were written with a goal in mind. You might not like the goal (I don't like that the opposing side is going to keep one of their houses and we'll get less money out of it), but our society has decided that these goals are worthy of being written into law. Amateurs think "they can't just foreclose on my home", and they're not completely wrong ... but the details are very complex, and often give a different answer. It's only crazy people like SovCits who take one buzzword (like "homestead exemption") from the text of the law and think that works like a magic incantation.
