The window to legally purchase a large-capacity magazines for California residents closed at 5 p.m. Friday, but, thanks to the state's draconian gun laws, a warning is needed for those who might want to use one of their new magazines in an AR- or AK-pattern rifle.
For a week, Judge Roger. T. Benitez made it legal to purchase magazines holding more than 10 rounds by declaring unconstitutional California Penal Code §32310. This allowed, for seven glorious days, Californians to manufacture, import, give, receive or buy large-capacity magazines.
What didn't change
What didn't change was California Penal Code sections 30510 and 30515 which define "assault weapons" in the state. We're not really concerned with §30510 which is a list of banned firearms that can only be owned in California if you had them prior to the early 2000s and registered them then.
What concerns new owners of large-capacity magazines is putting them in AR- or AK-pattern rifles purchased after 2017 or a pre-2017 rifle that was modified to have a "fixed magazine." Specifically, §30515(a)(2) and (b):
(a) Notwithstanding Section 30510 [the named, banned firearms], “assault weapon” also means any of the following:
(2) A semiautomatic, centerfire rifle that has a fixed magazine with the capacity to accept more than 10 rounds.
(b) For purposes of this section, “fixed magazine” means an ammunition feeding device contained in, or permanently attached to, a firearm in such a manner that the device cannot be removed without disassembly of the firearm action.
So, if you have one of these rifles that requires you to pull the rear takedown pin, separating the upper from the lower, in order to remove the magazine, then you may not put one of your new, large-capacity magazines in the rifle—at least in the state of California.
Doing so effectively makes your gun an "assault weapon" and illegal in the state.
So who can use these new magazines?
Any California resident who has their rifle(s) registered with the state as either an "assault weapon" from the early 2000s or a "bullet-button assault weapon" registered with the state no later than June 30,
2017 2018, can use 10+ round magazines in those rifles.