Use drawer slides; mount the drawer on the wall; attach the shell to the slides, so it pulls out. Shifty Desk / Hallway Stand by Daniel Schofield This is such a great storage idea! It can be a shelf and a drawer.
"New Jersey Concealment Furniture. The designers have created not just one or two pieces, but an entire range of furniture dedicated to concealed firearms storage." They're automatically cool because of the hidden compartments.