Question: what is ak 47 caliber?
Answer: The AK-47, officially known as the Avtomat Kalashnikova (Russian: Автома́т Кала́шникова, tr. Avtomát Kaláshnikova, lit. 'Kalashnikov's automatic device'; also known as the Kalashnikov and AK), is a gas-operated, 7.62×39mm assault rifle, developed in the Soviet Union by Mikhail Kalashnikov.