The RPK is quite accurate, and deals significant damage (Enough to tear limbs off) in the campaign. It can be found with an ACOG sight, Drum Mags, and Dual Mags.
The RPK in multiplayer is unlocked at level 6, and is a good weapon overall. The RPK kills in 3 hits at any range, 2 required if a headshot is achieved. It is a good candidate for the Dual - Mags or Extended Mags attachments, as it has a 40 round magazine, the rate of fire is fast (750 RPM) and the reload is quite slow. Using the Extended Mags gives the player a 80 round drum that reloads as fast as a normal box magazine. The RPK, despite being a light machine gun, can do pretty well in close quarters due to its good hipfire accuracy and high power output. Paired with Steady Aim and Extended Mags, it is a good candidate to 'spray and pray'. The RPK's main disadvantage is it's strong recoil. In order to counter that, the player must fire in burst or semi auto to maintain effectiveness at longer distances, as the RPK has no damage drop off, and can outpower most weapons at range if used wisely. The RPK can perform very well at middle ranges as a defensive weapon - it's power output at medium range is more than enough in most situations.
The RPK can only be found in the Mystery Box and supports a 100 round magazine. For the most part, it is quite similar to the HK21, however it trades a higher rate of fire for a slightly smaller magazine.
The Pack-A-Punch version of this weapon is called the R115 Resonator (Element 115 reference). When upgraded, it gains 25 rounds per magazine and becomes more powerful.