Kinetic Action HPA drum mag just arrived for my GHK RPK! : r/GasBlowBack
Airsoft GI - TSD RPK Support Weapon - Full Metal/Real Wood, Drum Mag Included, 'Nuff Said - YouTube
GUNS Magazine The RPK Squad - GUNS Magazine
Two Soviet 7.62 mm RPK squad light machine guns, the top one with a 40-round box magazine and the bottom one with a 75-round drum magazine - PICRYL - Public Domain Media