Story of the RPK-74 The 5.45x39mm RPK-74 was an evolutionary development of Mikhail Kalashnikov’s original 1940’s-vintage AK-47. The earliest AK (Avtomat Kalashnikova) rifle fired the then radically new M43 7.62x39mm round and was built around a stamped steel receiver. This 35″, 7.7-lb. infantry rifle legitimately changed the world. Alas, those early stamped receivers weren’t…