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 United States Army and Air Force issue M4 Carbine comes with the M68 Close Combat Optic and Back-up Iron Sight. The United States Marine Corps uses the ACOG Rifle Combat Optic and the United States Navy uses EOTech Holographic Weapon Sight. The AK-47 has a 41.5 cm (16.3 in) barrel and a 378mm (14.88 inches) sight radius. The AK-47 uses a notched rear tangent iron sight, it is adjustable and is calibrated in hundreds from 100 to 800 meters (100 to 1000 meters for AKM models). The front sight is a post adjustable for elevation in the field. Windage adjustment