His winning entry, the "Mikhtim" (so named by taking the first letters of his name and patronymic, Mikhail Timofeyevich) became the prototype for the development of a family of prototype rifles. This process culminated in 1947, when he designed the AK-47 (standing for "Avtomat Kalashnikova model 1947"). In 1949, the AK-47 became the standard issue assault rifle of the Soviet Army and went on to become Kalashnikov's most famous invention. While developing his first assault rifles, Kalashnikov competed with two much more experienced weapon designers, Vasily Degtyaryov and Georgy Shpagin, who both accepted the superiority of the AK-47. Kalashnikov named Alexandr Zaitsev and Vladimir Deikin as his major collaborators during those years.