What are good cles for getting a nuke on MW2?

I have tried and tried but everytime i put nuke on i fail. Im using my best cl- Tar 21 silensed Scavenger pro ninja pro and cold blooded but i keep choking and cant even get my harrier. Im not sure how to fix this. Its causing me to possibly have a nervous breakdown. Just kidding but seriously. Im using harrier Chopper gunner and nuke but i cant even get my harrier. Any help like what game type and such? Also please dont say nuke boosting.