This thread is going to teach you how to boost on MW3.
There is a possibility of getting banned, but this way is the best way not to get banned.

In This Thread
Classes
How To Boost
Notice's

Classes:
Any Gun's you want to level up
Tactical Insertion
Any 1 & 3 Perk
QuickDraw Pro
Specialist

How To Boost:
1.Appear Offline And Turn Theatre Recoding Off, Do it for guest aswell !
2.have 4 friends that have two controllers and Tactical Insertions
3.Inv one of them to your lobby, you should have 2People/2Guests
4.Search for a Team tactical until you find a demolition one.
5.Inv your friends

6.Get one person to plant the bomb at the start
7.Place your tactical insertion on your guest, once he dies, skip killcam and repeat.
8.Boost with the person who's boosting on your guest
EG: Person A Boosts on Person B's Guest and Person B boost's on person A's Guest.
9.Dont get your killstreak to high !
10.Once the round is over, plant bomb again.

NOTICE !
If you get over 40 000Xp that game's XP wont count, so leave after 30 000 XP and get your friend to re invite you.

If randoms join, someone say random's and everyone leave really fast!

Hope This Helped