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.
Comparison of the AK-47 and M16 be a simple, reliable automatic rifle that could be manufactured quickly and cheaply, using mass production methods that were state of the art in the Soviet Union during the late 1940s. The AK-47's barrel and bolt were milled out of a steel billet and hard chromed. Its receiver was originally designed to be stamped from sheet metal with a milled trunnion insert. However, there were many difficulties during the initial phase of production causing high rejection rates due to faulty receivers. Instead of halting production, a heavy forged steel machined receiver was substituted for the sheet metal receiver. This was