Bootleg Gunz:The Bazaar of Bizarre Guns - "A .22lr pen gun made from a $3 automatic center punch tool. The key ring is simply pulled back and released to fire. These same
Hardware store zip guns -The Firearm Blog
PenGun. ZipGun
Man charged over home-made pen gun
Firearm Archive
Pin on try stick
Close Up of The .25 Cal Zip Gun I Made (Details in Comments) : r/guns