This is the code that's currently being used in the new system to calculate xp:
PHP Code:
double newXP 0;
newXP += (((player.maxHits player.maxHeadshots*2) / 8.0) + player.maxKills) * 2.5// the light weapons part
newXP += (player.maxKills_h 3); // Heavy weapons
newXP += (player.maxRevives 4); // Revives
newXP += player.newDifXP// EngineeringXP + Battle Sence 
There are plans to perhaps handle each weapon separately but that's not done yet.