Lego minifig compatible Custom SI-Dan Toys AK47 is highly detailed. Also known as the Kalashnikov or just AK. A gas-operated, 7.62×39mm assault rifle developed in the Soviet Union by Mikhail Kalashnikov in the aftermath of World War II. The number 47 refers to the year it was finished. The AK-47s used a long-stroke gas piston above the barrel. Available in transparent at a highly reduced price so it can be painted whatever colour you want.