The Kulakov grenade launcher was a prototype grenade launcher designed in the USSR during the Second World War.
The grenade launcher is made from a cut-down Mosin-Nagant bolt-action rifle. The Mosin-Nagant is sawed down, with a stock pad and pistol grip added to facilitate recoil control. A large revolving foreend was added in front of the sawed-off Mosin-Nagant, which held five 44×15mm grenades. The Mosin-Nagant would be loaded with blank cartridges in order to launch the grenades.
The cylinder rotates automatically; after firing a shot, expanding gases are trapped in a chamber around the muzzle, forcing the barrel to move forwards, breaking the obturation of the rifle chamber, cylinder, and launcher barrel, and forcing the cylinder to rotate. A recoil spring would then force the barrel back. The user can then cycle the action, load another blank cartridge, and fire another grenade.