Hog Rifle for my father

[Great-Kazoo]

There's no issue buying an AR in CA. Bullet buttoned AR's line a good portion of CA gun shop shelves.

For an option being able to retain the AR platform
ARES SCR. A web search will get you to a few forums where it's been discussed. Seems to have good reviews across the board.
http://www.aresdefense.com/?page_id=729

Our daughter is buying one. This way she has a CA legal "AR" style rifle for pest control. She has something now, but wants a CA specific legal one for walking the property. Suggested she wrap it in that mossy oak tape for complete distraction.