The Kresimir is honestly the most bonkers weapon I have come across in a long while. Made by IM Metall in Croatia at the beginning of the Croatian Homeland War circa 1991, this is a semiautomatic grenade launcher. Most grenade launchers fire a big cartridge with an explosive warhead, but not this thing. Instead, it uses a 5-round magazine of M50 hand grenades with percussion fuses. A second magazine holds 7.62x39mm grenade-launching blank cartridges. Pulling the trigger drops two strikers in succession; first one to ignite the hand grenade fuse, and then one to fire the launching cartridge. What could possibly go wrong?
When you do fire, the recoil cycles the whole barrel and bolt backwards like a long recoil action, although it appears to be blowback and not locked. This loaded a fresh grenade in the barrel and leaves it ready to fire again with the next trigger pull. We don’t know how many of these insane creations were actually made, but I have multiple reports of their actual wartime use from veterans of the conflict.