There is a crossbow with explosive darts and 1 with normal darts you get it at level 33
the crossbow i believe
You have to be level 32
Once you unlock it, you automatically have explosive tips.
In Black Ops multiplayer you unlock the AK-47 at level 38.
You unlock gold camo in black ops, when you reach prestige level 14, level 25.
You get to level 50
When you rank up to level 35 you will unlock it.
You have to get to level 44 and then pay the $2000 to unlock it
you unlock more emblems
Level 44
get to the level where you unlock it :):P
Level 27, for 2000 cod points