The Striker is unlocked at level 48 in Multiplayer and level 33 in Spec Ops.
You unlock Claymore at Level 53 in MW3! :-)
Weapon level 5
lvl 34
You unlock the ACR 68 at level 56. Hope this helped! :)
You level up your secondary that you want attachments on.
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
find the custom class and unlock them
There is no way you can unlock Matt striker on WWE Smackdown vs raw 2009
Poop
What you have to do is level up till you can buy it or find cheats online but i have already cheacked for you could not find any :/
The guns themselves can gain experience, and the more you use them, the more they get. When they level up, you unlock attachments, proficiencies, and skins for them.
Yes, you can i did it in the last level of mw3