ATF Pistol Brace Rule. Surrender My AR Pistol?

Finally finished my CA AR Pistol..... Then the new rule dropped.
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Can't Register as an SBR in California. California doesn't allow any NFA items period...
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Our options in ca.
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Make it a rifle....
Destroy the entire gun......
Destroy the brace so it can be reattached......
Surrender the entire gun......
Surrender the brace......
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Not sure when ATF was granted authority to make laws. As far as I know they enforce laws not make them. Maybe that's why it's a RULE not LAW......
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Im sure this will be challenged in court, but for now we don't have long to decide what to do.