How do you get Grim Reaper in Call of Duty Modern Warfare 2?

I thought this was much harder than it actually is, you really only have to get 5 Predator kills in one life rather than 5 kills with 1 Predator Missile as the challenge specifies. When you earn a killstreak and die before using it you still keep it...So the easiest way to be sure you get it would be to earn a predator but die before using it. Do this a couple times and simply call 1 right after the next to get all 5 kills in 1 life, thats how i got it.