The AEK-971 is a selective fire 5.45×39mm assault rifle that features a balanced automatic recoil system, developed at the Kovrov Mechanical Plant (KMZ) by chief designer Stanislav Ivanovich Koksharov, also known as Sergey Koksharov, in the late 1970s and 1980s. Variants in 5.56×45mm NATO (AEK-972) and 7.62×39mm (AEK-973) were also developed.