You unlock Claymore at Level 53 in MW3! :-)
find the custom class and unlock them
Shoot a claymore and kill them this is hard
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.
You unlock the ACR 68 at level 56. Hope this helped! :)
Weapon level 5
Yes, when playing MW3 and you have a specialist and you unlock a certain perk so many times it does become pro.
You cannot unlock it, only in Black Ops.
Plant two bombs in hardcore search and destroy.
most likely mw3 will have guns and attachments that you will unlock from level to level.you probably will not see and point system to buy attatchments for guns
you get to unlock any one thing including guns, special grenades, claymores and attachment etc. (note i have herd that if you unlock a gun and get it gold it resets to lv 1 after you prestige again)
there is core maps which you get with the game and there is some you need to buy the dlc to play on
You level up your secondary that you want attachments on.