This is one of the more contentious issues in California law. On one extreme, we have the optimists who believe that the only thing which matters is that you have a magazine lock installed on your rifle, even if a magnetically affixed tool is connected to it for use in detaching the magazine. On the other, the more conservative side believes that constitutes a normally functional magazine release and that any tool which remains attached to the rifle by itself, constitutes a felony.
I'm attempting to collate useful information, sourced from public records where possible. Case names and dates are desirable, and are much more persuasive to the general populous. If you have any, please share.
The following is a link to a memo by Sean Brady, an NRA-affiliated attorney, regarding attached bullet button tools: http://www.calgunlaws.com/wp-content/uploads/2012/05/aw-weapons-modifications-memo.pdf
The following excerpt is from Bill Wiese, posted to a Facebook Calguns group on 9/5/14:
1. In 2009-2010, #1 - defended by TMLLP/CDM. It was for MagMagnet or other similar tool. I believe the individual got a wobbler possession charge and not mfg charge so he may be able to go 17b and get a misdemeanor and eventually recover gun rights. Bust #1 back in 2009 time frame had a whole memo on TMLLP's website. Now that it's M&A it still may be around elsewhere.Gonna be LA area that's all. It described evertything about the case but not name etc. just the 'bill of particulars'. I do recall he was set up at least for a future 17b motion due to wobbler status - thus the charge was AW possession as opposed to transport or mfgr, both non wobblers. Qualifications beginning 'Bust #1' were added based upon later posts, and inlined to preserve conceptual flow
2. 2.5 yrs ago: dude buying hicaps in Reno was followed back to CA by DOJ. Instead of CHP pullover in Truckee they followed him home to bay area, and let him go in. They had an insta-warrant and went in - not only did they find mags but they found a BB maglocked rifle with a "little red magnet" override over it. Busted also for AW. Unclear how the plea went.
3. Last year an individual was selling these devices at Cow Palace gun show. Unknown 'brand' of mag BB override but irrelevant. Was photographed/videoed by DOJ demoing the mag attached to the BB - and was a full -house featured gun. [Other vendors don't do this and hide behind things by putting them on so-called 80% lowers or featureless guns where BB status is irrelevant.]
4. I know CGF affiliated Lawyer Adam Richards has dealt with or initially counseled several folks with these issues and is aware of numerous such busts in Sacto area. CGF has ahad defense support requests for these too, for which we turned folks down for funding (although we'd help if we could on any peripheral issues.]
5. I'd say there's been about 20-40 arrests. Unsure of conviction rate but it's gotta be 50% range (sometimes if someone is lucky they just keep the gun and if the dude is smart he just lets it ride out with no charges and doesn't ask for the gun back.) I have not heard of any AB2728 resolutions esp given a compliance device was intentionally overridden (as opposed to old guy forgot to reg his AW, etc.)