They are out there.. But you will be hard pressed to find someone that will be willing to ship it to a CA ffl much less convert it to be CA legal. Aside from making it semi auto you would have to make it impossible to open the feed cover without the use of a tool... Or you could remove the pistol grip and see if you can get a spade grip set up going if you wish to be able to open the feed cover.
If my answers frighten you then you should cease asking scary questions.
We the people are the rightful masters of both Congress and the courts, not to overthrow the Constitution but to overthrow the men who pervert the Constitution.
We keep one foot in the water.