My K/D ratio is about 2:10.
And i have had about 40 nukes.
Run 'N' Gun is the way forward, but don't go running into them all with an M4A1 and expect to kill them all.
Get the UMP-45 with FMJ, and with the Lightweight and Marathon pro perk in one class, then flank there ***! (Come up round the back of them, or the side)
If you want to get a few kills with one shot, get the RPG and Danger close perk in one class, then go soot it in buildings where they are hiding, it's a bit noobish, but it racks up them kills!
If you want to go for the nukes, have your killstreak set out like this:
1st - Harrier strike #7
2nd Chopper Gunner #11
3rd Nuke #25
At first just Run 'N' Gun, then chill for a while, but try not to turn it into camping!
Then once you get to 7 kills, sit back and let the Harrier take you to 11 kills, then with the chopper gunner, that should get you p to 25 if your good enough and on an open map.
Try to play a little hardcore games, it lets you use other perks other than stopping power, without it on normal games, it takes the p*ss to kill them.
Also, play game modes with a long time limit or a score limit, then you can get more kills.
If your on ps3 add me? sheeyan_2k10.
Hope this helped?