I live in California and I just purchased a Spikes tactical lower ar receiver online yesterday. I know I have to install a bullet button and I intend to build it so it is completely legal in Ca. As unfortunate as the laws here are.. Anyway, I've been trying to research what is a legal California AR15 and I keep getting mixed results so I thought I would turn here to ask.

My understanding is that you can have a collapsible stock, pistol grip and flash hider as long as you have a fixed magazine. My understanding too is that an AR15 with a bullet button has a fixed magazine because you can not eject it without a tool.

Is my understanding of a legal AR correct?

Also what about a bullet button magnet? I've seen these lately and they say it's a "tool" if you don't keep it on there but only use it to eject the mag. Are bullet button magnets legal?

If you guys could help me out I would really appreciate it!

Thank you!

Former Cali resident here.  I try to keep up with the laws there, but I have not lived there in three years, so take what I say with a grain of salt.  You might want to poke around on the calguns forum.  They get a lot of flack here, but there is a lot of good information pertaining to the California gun issues.

ETA:  Your question might get some better replies in the CA hometown forum here.
http://www.ar15.com/forums/f_8/11_California.html

The bullet button magnet is also referred to as the felony magnet.
In other words, it is NOT legal.
Once it is attached to the rifle, it is part of the rifle and not a tool.

Legal for out of state use. Or with your .22LR conversion kit. Just make sure to pop out your mag magnet before removing the .22LR conversion kit. Even then I would just get a regular bullet button unless you want to quickly swap between .22LR and centerfire.