You say you're moving into an apartment, so I suspect the landlord will take a dim view of your cutting a big chuck of drywall from between studs or cutting out part of the floor to install a flush safe, but those are good ideas.
I second the GunVault idea. I have one bolted to the bed frame. That would be great for the handgun.
Yet another idea can be seen on truckvault.com's web site. They make secure, locking drawers that were designed to be bolted into pick up truck or SUV beds. They also make one that can be bolted to your bed frame:
http://truckvault.com/OtherProducts_BedVault.aspx This would provide a reasonably secure place for your rifle while still maintaining reasonably rapid access.
Not sure about the exact dimensions of your WASR-10, but I've seen some clever ideas for somebody who's handy with tools. One interesting DIY idea is to put a false bottom in a large dresser drawer. Cut a piece of plywood to fit closely, but not too snugly and you can have a space a couple of inches high and the entire width and length of the drawer. Add hinges or doors, etc. depending upon your wishes and woodworking skills, or just have a single slab hiding everything in the space below. Put light clothing on top that can be moved easily and quickly and you're good to go. Now somebody tossing your place may find your hidden rifle fairly quickly. Dumping drawers onto the floor is pretty much standard procedure in a burglary (or police search for that matter). If you're *really* handy and have the time and patience, you could design such a drawer that will keep everything in it from rattling and a lid that is locked in place until you insert a small pin in a tiny hole, or position a strong magnet in a particular spot to release the latch. That way they'd have to smash the drawer to get into it.
Another similar idea is a false bottom or false rear in a lateral file cabinet drawer. If you're handy with wood working and tools, you may already have furniture in your possession that you could modify to create a hiding place. For example, my kitchen table has the flat table surface mounted on a box like frame about 4 inches thick. The table legs bolt to the box frame. It wouldn't take too much to make a bottom for the box and create a place to store the rifle. Same could be done with a coffee table, entertainment center or the underside or rear of a dresser.
There are a number of firms that manufacture furniture with hiding places. You can probably get some additional great ideas from perusing their web sites.
http://www.greatstuff.com/furniture.html
http://lumberjocks.com/topics/5445
http://www.instructables.com/id/Cheap-secret-compartment!/
http://stealth-vault.net/products/
http://www.collectorsweekly.com/articles/finding-secret-drawers-and-hidden-compartments/