Since I did not understand LogicMan's post, let me explain the bullet button. California in 1993 banned by name virtually every AR on the market at that time, and further banned any semi-auto rifle that did not have a "fixed magazine." A fxed magazine was defined as one that requires a tool for its removal, which at the time meant that mag releases buttons had to be disabled through the use of a "Prince" device (that acted to freeze the button by use of a small screw through the face of the release preventing it from being depressed). ARs thus had to be opened up and loaded internally with a max of 10 rounds. Along came a man with a bright idea, and the Bullet Button was born. In essence, the mag button is too long to be depressed, but the center section is a separate piece that attaches to the mag release rod, and is too small to be depressed by a finger. Instead, a tool of some type must be inserted into the center of the button to depress the rod, the "tool" it was designed for being the tip of a bullet. The BB thus complies with the literal terms of the statute. (There are other devices as well, one that magnetically attaches to the face of the button but is only legal if removed before commencing fire.)
Senator "DeLeon, along with then Senator (and now convicted felon) Lela "Gu Runner" Yee, proposed to ban the bullet button in 2013. After Yee's arrest on gun running charges (talk about hypocrisy), the bill was withdrawn. Recently, current Lt. Governor (and former SF mayor and gubernatorial candidate to replace Gov. Brown) Gavin Newsome has started an initiative drive to not only ban the bullet button but to require ammunition purchase IDs (issued after a background check), instant background checks at the time of purchase of ammo, ammo purchase limits with reporting to the police, and paper and video recording requirements by (now licensed) ammunition sellers in face to face transactions (eliminating internet sales). Senator DeLeon has promised to revive his bullet button ban, a bill that would redefine "fixed" to require that the mag could be removable only by disassembly of the action. Between the two, the intent is to ban semi-auto Evil Black Rifles from the state, to make gun ownership burdensome and expensive, and subject to intrusive public monitoring, all in the name of the public good.
If Newsome is elected governor, as seems likely at this point in time, and with a commanding majority in both houses of the State Legislature, the future of gun rights in California is bleak. For those of us who reside here, buy now and buy often. Stock up on ammo, because things may soon be worse than the worst day of the last drought.