Play as a medic in Hardcore mode with a friend. Go to an area where you are 
notified that you are leaving the combat zone. Have the other player walk out
there. Once they die, run in the area, and use the defibrillator to revive them
to get 80 experience points. Repeat this as many times as desired. 
Note: This can be also be done by finding a safe location, intentionally killing
your partner, and then reviving them with the defibrillator. Each time this is 
done you will get 80 experience points but also lose 15 experience points for 
killing a teammate.