Once you unlock it, you automatically have explosive tips.
You have to be level 32
There is a crossbow with explosive darts and 1 with normal darts you get it at level 33
no you cant because there is a explosive on it with a sticky mold on the btip of it. (its kinda like a semtex, But an Arrow.)
The Spas-12 is OKAY when upgraded. If you have a choice, however, always go for the crossbow. The upgraded crossbow makes zombies attracted to the explosive bolt.
the crossbow i believe
No, there is no attachment with a scope for the crossbow. no there is no attachment to the crossbow at all.
if Ur talking about story mode need to equip the crossbow and press left on the control pad to switch to explosive tip
yes.
a crossbow is weapon you can use in Black Ops. It shoots out a grenade thing that explodes and can stick to you, its sort of like a semtex. It can also shoot sniper bullets. The semtex-like bullets are better for close range.
You get to use it in both campaign and multiplayer, but only as secondary on campaign, and in multiplayer there are entire matches for crossbow.
depending on the round, you can use explosive weapons (ray gun, crosbow exp. tip, m72 law, china lake, and grenade), or shoot their legs (very hard) monkies will kill the zombie,gershes destroy the zombie, and upgraded crossbow destroys zombie.
Just do a bunch of combat training and watch tips on YouTube.