What is the no kidding impact of the most recent legislation that was passed in California?
1.) Rifles with detachable magazines can no longer be sold after 2016. Existing detachable-magazine rifles have to be sold/stored out of state, registered, or permanently modified such that the magazine cannot be detached (e.g. no more CA "bullet buttons" unless it's registered as an "assault weapon"). Also, no transfers of registered "assault weapons" (now defined as any rifle with a detachable magazine) within the state, unless they can be permanently modified to no longer have detachable magazines.
2.) No more possession of any magazines >10rds. The previous restriction from 2000 was against buying, selling, or importing said mags, but so-called "pre-ban" mags were allegedly OK to keep. After July 2017, all existing mags >10 rds must be sold, turned in, or destroyed, unless you're prior LE.
3.) It will be illegal to loan a gun to a friend without a state background check. So sorry, you can't borrow my pistol for that NRA course.
4.) An I.D. and background check will be required to buy ammo in the state, and a database of all ammunition buyers will be created by the state of CA. (starts in July 2019).
Additional info can be found
here,
here, and
here. The third link provides an interesting Q&A.