Fireteam Match Making Never Works?

[RADIORAHEED]

Whenever I group up with a few of my friends as a fireteam and press the SEARCH ****on, the timer runs out and says no suitable games found. This will happen over and over without fail. How can I get into a game with my friends?

[RADIORAHEED]

Anyone else having this issue? 4-person fireteams seem to work fine for me but 2 or 3 people and I can never find a game.