After examining samples of the M16 captured in Vietnam, Soviet engineers recognized that the performance capabilities of the new 5.56x45mm outpaced those of their 7.62x39mm. Whereas the latter cartridge’s velocity and trajectory caused it to have significantly degraded performance past 300 yards, the 5.56x45mm (which moved a 50- to 60-grain projectile in the eighborhood of 3,200 feet per second [fps]) performed well out to 600 yards, all with lighter ammunition weight and lower recoil. As a result, the Soviets set about developing a comparable cartridge. Some in the upper echelons of the Soviet defense industry had already been considering “refreshing” the AK and its cartridge—the M16’s arrival simply accelerated their plans. After a great deal of research, testing and comparison against captured 5.56x45mm rifles and rounds, the new Soviet cartridge to emerge was the 5.45x39mm M74 (indicating its year of appearance). Propelling a lightweight 50- to 60-grain projectile at around 3,000 fps, the new round appeared to answer all the required design parameters for the new round: flat trajectories, low recoil and lightweight ammunition.

Century Arms AK74 rifle chambered in 5.45x39. Model M74 Sporter. Know your states laws, will not ship to ineligible state.