[Roguish Lawyer]

Originally Posted by vsvo

According to §978.20(b), Article 2, Chapter 12.8 of the California Department of Justice Regulations for Assault Weapons and Large Capacity Magazines, "'flash suppressor' means any device designed, intended, or that functions to reduce or redirect muzzle flash from the shooter's field of vision."

Therefore, based on your description of its function, the brake falls within the definition of a banned feature. The original definition promulgated by DOJ specifically excluded muzzle brakes, until someone figured out that brakes can reduce flash. Since DOJ interpreted flash suppression as the legislative intent, regardless of device name, they modified the original definition.

As to whether it's legal on your rifle, I would say yes, since your rifle is already registered as an assault weapon. I didn't see anything in the statutes prohibiting modifications to registered weapons, except for a section on removing banned features and cancelling the registration. How does adding one more evil feature from the list of evil features make it more evil?

But when you change the upper receiver, are you making a new gun for purposes of the statute? Does the pre-ban gun become a post-ban gun? If you change a key characteristic like adding a flash suppressor?