If you only play Teamdeath Match, it will take you longer to level up. Demolition is a mode that could get you lots of points and I found that if the game drags to the third round, there are even more points.
I remember playing in this mode and a friend of mine told me to let the other team win in the second round. It dragged to the final third round and if you could win in the final round, more points would be awarded.
Map Combine, using an assault rifle with 37 kills.
Player Japan LIfe.