There are a variety of home firearms concealment products on the market, and some are quite good.  Consider this bookcase in the Criswell Concealment Collection from Creative Designs by Logan.  The bookcase has several concealed compartments suitable for storing long guns and hand guns in addition to other valuables.

The basic unit comes with:

• two lockable pull-out shelves
• two lockable cabinet drawers or doors
• electronic lock
• stain of choice

Custom options include size, wood, lighting, shelves, locks, interior of full cabinet doors to fit your needs.  MSRP is $4,999.