The law says FIREARM...NOT simply handgun.
Technically, under the law an AR-15 stripped lower is a firearm and can result in a 626.9 felony charge.
Doesn't that second paragraph in 626.9(c)(2) mean that 626.9 doesn't apply to firearms other than pistols, revolvers, and concealable guns? I would think 626.9 is the "section," so I can't imagine another interpretation of it.
(c) Subdivision (b) does not apply to the possession of a firearm
under any of the following circumstances:
(2) When the firearm is an unloaded pistol, revolver, or other
firearm capable of being concealed on the person and is in a locked
container or within the locked trunk of a motor vehicle.
This section does not prohibit or limit the otherwise lawful
transportation of any other firearm, other than a pistol, revolver,
or other firearm capable of being concealed on the person, in
accordance with state law.