“The pen is mightier than the sword” said every gun (and sword) hating journalist ever. But if you are in need of an ultra concealable weapon to punch holes in tin cans and don’t want to file the paperwork and pay the taxes for .22LR firing pen, you should consider hw97karbine’s very cleverly designed air powered pen gun. He explains how to build the airgun on Instructables, the only catch being that a lathe is required.

This handy gif explains how the mechanism works …

If you need something more powerful, maybe you want to take on a shark or dinosaur in hand to hand combat, then take a look at hw97karbine’s latest invention, the STBD (Strike Triggered Ballistic Device), a compact and concealable captive bolt gun (minus the “captive”).