There is no specific ban on gun braces in California, but they are prohibited by the National Firearms Act of 1934. The NFA prohibits the possession of any firearm that has been “made” or “altered” to fire more than one shot with a single pull of the trigger. A gun brace would fall into this category, as it is designed to increase the accuracy and stability of a weapon when fired. For this reason, it is advisable not to possess a gun brace in California or any other state where they are illegal.
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.