Most of the south part of South Cal are in Zone 2.
(a) Lights of any size or voltage may be used to take furbearing or nongame mammals only in the areas described in subsections (b) and (c) below, and only under the following conditions. We're in zone 2 (subsection c)
When you get into the "remainder of the state" is where you start seeing more restrictions on volt size and it says must be handheld or worn.
I would look into this better before you take out a gun mounted light.
Pretty sure it was Toua70 who emailed DFG and was told that this was a mistake in the posted regs. You CAN have a gun mounted light as long as it's less than 9V.
I'm hearing though that certain counties don't allow shooting at night regardless of DFG rules and regs. Still researching this but hearing Riverside Co is one of them. Seriously hope not! Anyone already know this?