The famous Avtomat Klashnikova Model 1947 (AK47) is, along with it's scores of variants, the most widely used and manufacutured assault rifle in the world. Developed orginally for mobile units of the Russian Army, the AK rifles have found their way into the hands from hundreds of other militaries, as well as terrorist groups. Caliber of the orginal AK47/AKM was 7.62x39mm. The 7.62mm caliber has been phased out in Russia, which now favors the 5.45x39mm, chambered in the AK74.
In the days of the Cold War, the USSR made and distributed countless AK47 assault rifles.