Alright well first off if you havent watched my video on how to make your self host then go watch it.
http://www.actionhacks.net/game-Cheat-media-f17/360-and-ps3-mw2-host-cheat-and-more-t227.htm
Well first off you should have your 360/PS3 bridge and have the programs. Check my other tutorial for them.
Alright well I am not going to get into to much detail into this one because it is by far the easiest.
First open up wireshark and colasoft.
Then get into a cage match with a friend and have them just sit there so there arent extra packets coming in.
After your in a match choose a automatic gun(Just so you can figure out how to do it) and start recording packets and shoot your gun for about 4 seconds.
After that stop capturing and look for the most recentish packets and find the ones that are the same or very similar.
Next save that go into colasoft and send the packets that are similar\the same.
Then shoot your weapon. It should be going alot faster. Good luck!
Post your issues and I'll try and help you out.