I think it's around rank 4. I'm pretty sure the last one is around rank 63.
But idk what console you have (i have wii. Terrible mistake choosing wii over xbox. Stupid IW and treyarch don't really care about wii and there are maybe at least 5 killstreaks not on wii but on other consoles).
you can unlock it with you're first killstreak award unlock
Escort Airdrop- Support Package
You unlock Claymore at Level 53 in MW3! :-)
Get a 2 killstreak with bullets while in mid-air
Get all 3 killstreak rewards within 20 seconds
Kill an enemy before they earn a 10 or higher killstreak reward
use hardline and then use the specialist killstreak set because every first point/kill will have 2 times the same thing you get without the specialist thingy
find the custom class and unlock them
A M.O.A.B is a 25 gun streak. 24 with hardline
a moab is a 25 gun streak only 24 with hardline, which means you can't use killstreak rewards to get a moab in mw3 but in mw2 you can
There are around twenty cheat codes for the Call of Duty MW3 game for the Xbox. Some of the cheat codes are the secret killstreak, gold camo, and easy XP.
As Special Ops in MW3 has it's own ranking system you may unlock call signs in there however, they will not transfer over to the actual online lay as the criteria to unlock them is different.