Visiting California from Colorado

Hey everyone! I haven't posted in the CA forum before, but I am now in hopes that I can get some answers.

I live in Colorado and I have a sister that lives in Agoura Hills. I'm flying out to visit her at the end of August and she wants me to take her and her boyfriend shooting for the first time. Most of my guns are NOT CA legal due to AR and hi-cap restrictions, but I do have an XD9SC with ten round mags that, from my understanding, IS CA legal.

My question is this: What do I need to do to bring my XD with me and not end up in trouble?

I called a gun shop out there and they said that as long as I use my ten round mags, as a visitor there isn't anything else I need to do to bring the gun into the state. No registration or paperwork at all.

Is that true? I hear tons of horror stories about CA gun laws and want to make sure I don't do anything wrong.

Thanks in advance for any help!

Since you're flying out, you will already have everything you need to transport "an XD9SC with ten round mags" namely a 'secure locking container'

As you move around simply keep the unloaded pistol locked inside the container and you will be fine.