Please remember a few things:
If we thought of it, the BGs probably thought of it. Crooks routinely go through bookshelves and shake out books, as many people hide money in the pages. A hollowed out book or those "book safes" are not a great idea.
Those little plastic fire safes have HANDLES; even the dumbest meth-head will grab those FIRST, as they know that's where the good stuff will be. If you have one of those, fill it with rocks and hide your guns elsewhere. If you're lucky they'll grab the "safe" and run.
The job box isn't a bad idea, but again, it has handles. Bolt It Down! Assume you're going to be robbed by 4 healthy, athletic hoodlums and anything under ~ 1000lbs needs to be bolted down. This goes for real gun safes as well. Don't believe me? A pawn shop owner about 15 miles from here was victim of a home invasion by......four 20-something men who all looked like they spent plenty of time lifting weights and running. Unfortunately he was taken by surprise and held hostage so his security system, safes, etc. did no good....
The only things that work are hiding (but you better do a darn good job), and anything that will increase the amount of time needed to make off with your stuff. The steel cable suggestions aren't bad. I wouldn't be surprised to see crooks with bolt cutters ($10 at Harbor Freight!), but a cheap pair would have a tough time with cable. The locks on that job box, though.....
I would attach to something more substantial than the bed, but that might be too destructive for an apartment.....do your best.
I would definitely suggest the disabling idea. They may get your guns, but they won't be able to use them. Most crooks wouldn't be able to figure out how to fix the gun, even if they found the parts. Even something like a recoil spring might be beyond their ability to repair, and very easy to hide. Got an AR? It's pretty easy to pull out the bolt or firing pin, and those parts could go in a LOT of places.
