Exp in Private Match AGAIN AFTER PATCH!! :)

[Exotickiller]

1. Get a Friend to invite you to a player match lobby
2. Go to your playercard and while your there have them change the lobby to combat training
3. Have them change the map and gametype to anything but done leave your playercard
4. Have the host leave
5. The person on their playercard hit a to get rid of the error that pops up and b to get out of their playercard
6. the person that was in their playercard invite the original host back
7.The new host (person that was on their playercard switch the lobby to wager match and hit find match and QUICKLY HIT B AND CHANGE THE LOBBY TO PLAYERMATCH
8. Now youll be in a private match searching where you can only invite the perople you want to play with and you will get XP So you can do sniping or whatever or boost
9. Enjoy

[Tempest]

They patched this already with TU#11.
...Assuming your talking about Black Ops with the information given.
You get deranked back to level 1, but the "good" side to it is you don't lose the Prestige your already on.