An extremely effective tactical method used in Battlefield 3 whereby 3 or more soldiers all select support class and equip the PKP Pecheneg.
They then proceed to locate a small corridor, prone, hold the trigger and very slowly crawl forward.
Your opponent will not be able to counter this due to the ridiculous amount of bullets in such a confined space.
Reloading is made safe by the fire of those around you.
This is a proven method on maps with long narrow corridors such as the locker rooms of Operation Metro and the side corridors in the tunnel of Damavand Peak.
"The one thing you need to know about the PKP Worm is to stay low and keep firing. PKP 4 Lyf"