These limitations led to the development of a hybrid system, where the missile was fired through the barrel of the tank's main cannon. The first generation of this concept was the Obiekt 775 tank, armed with a 125 mm smoothbore gun that could fire high explosive unguided rockets, or a radio command guided projectile. The guided projectile was called "Rubin" (Ruby) and the unguided projectile called "Bur" (Drill). The tank could carry 24 Rubin missiles and 48 Bur rockets. The project was a failure, as the Rubin's shaped charge warhead was not effective enough, and there were concerns that the missile's command link could be jammed.