 (The SKS – an interim, semi-automatic, weapon adopted a few years before the AK-47 was put into service – was designated a carbine, even though it's 20" barrel was significantly longer than the AK series' 16.3".This is because of the Kalashnikov's revolutionary nature, which altered the old paradigm.Compared to previous rifles, particularly the Soviets' initial attempts at semi-automatic rifles, such as the 24" SVT-40, the SKS was significantly shorter.