What about these "hidden" safes? Seems like a pretty smart way to secure your firearms, yet still have easy access to them if you know where they are.
http://tacticalwalls.com/

I was thinking about this one in particular, large enough for 2 rifles and plenty of room up top for magazines or a flashlight, and it is lockable:
http://tacticalwalls.com/shop/series...insert-bundle/