AK-74 be used by the majority of countries of the former Soviet Union. Additionally, licensed copies were produced in Bulgaria (AK-74, AKS-74 and AKS-74U), and the former East Germany (MPi-AK-74N, MPi-AKS-74N, MPi-AKS-74NK). Besides former Soviet republics and eastern European countries, Mongolia, North Korean Special Forces, and Vietnamese People's Naval infantry use AK-74s. The AK-74 was designed by А. D. Kryakushin's group under the design supervision of Mikhail Kalashnikov and is an adaptation of the 7.62×39mm AKM assault rifle and features several important design improvements. These improvements were primarily the result of converting the rifle to the intermediate-caliber high velocity 5.45×39mm cartridge.
AK-47 of countries, with "quality ranging from finely engineered weapons to pieces of questionable workmanship." As a result, the AK-47 has a service/system life of approximately 6,000, to 10,000, to 15,000 rounds. The AK-47 was designed to be a cheap, simple, easy to manufacture assault rifle, perfectly matching Soviet military doctrine that treats equipment and weapons as disposable items. As units are often deployed without adequate logistical support and dependent on "battlefield cannibalization" for resupply, it is actually more cost-effective to replace rather than repair weapons. The AK-47 has small parts and springs that need to be replaced every few thousand