There are no specific gun braces that are banned in California, but any modification to a firearm that could make it easier to shoot would be considered illegal. This includes adding a brace or stock to the weapon, which would make it into a Short-Barreled Rifle (SBR) or a Short-Barreled Shotgun (SBS).
If you’re unsure whether a certain accessory or modification is legal, it’s best to err on the side of caution and consult with an attorney who specializes in firearms law.
Stephen Answered question August 1, 2022