Level 22 (Master Sergeant I)
When you first play, you must use default classes until you level up to Level 3 (I think). This is when you unlock custom classes, and you start with the m4a1
You must reach level 70.
Like with any gun title, you must unlock all the attachments for it.
Complete the "How The... " challenge by killing someone with an explosive that you shot using bullet penetration. You must be a certain level to unlock this.
you must get to level 80 10th prestige.
Kill someone who is in mid-air. You must be a high enough rank to unlock this.
No, you must have the attachment already unlocked
Kill 300 people who are still dazed by a stun grenade. You must be prestiged to unlock this.
You must purchase the Resurgance Map Pack for 1200 Microsoft Poins or FREE on the PlayStation 3 and PC.
First you have to unlock the gun you want to put it on and then either the silencer, like any other attatchment is already unlocked, or you will unlock that in time too. Maybe you just have to level up.
It's on online multiplayer and you must be level 10 to unlock this. It's under killstreaks when you have the callsign and killstreaks. You have to get 9 kills without dying or 8 if you have hard line. Then you will get a pave low which you activate by pressing the button that has pave low on it.
You must have level 55 and go to ''Create Class'' and you will see it ''Sidearms''