This. Although these days, it seems like "standard" .223 starts at 62 grains.
CA is in the same boat NY is. You can either have a fixed 10-round magazine that requires you to break open the gun and load from a stripper clip, or you can go "featureless"--no muzzle device/threads, no pistol grip, etc.
Actually, the way CA's law is written, it's less restrictive than NY's. A lot of CA-legal manufacturers tell their customers that their products are okay in NY, but NY demands that a rifle be rendered unable to accept a detachable magazine.
All of which is funny, because good gun owners and shops really struggle to follow this ridiculous law, while less-than-law-abiding folks ignore a law that almost nobody has been charged under. I believe we actually had our first SAFE Act possession arrest last year--some guy "well-known to local police" decided to wave around his non-compliant AR on his front lawn. Virtually all of the thousands of "SAFE Act prosecutions" were arrests in NYC that got bumped from misdemeanors to felonies under the law.