America's Army/RPK Automatic Rifle
From StrategyWiki, the video game walkthrough and strategy guide wiki
The RPK Automatic Rifle is the Opfor equivalent to the M249 SAW, except with 75x4 bullets initially. It comes with a bipod and can be fired in semi-automatic mode.
The RPK in America's Army is probably either the original RPK with a drum magazine (http://world.guns.ru/machine/mg15-e.htm) or the RPK-74 (http://world.guns.ru/machine/mg16-e.htm).