I need the binoculars gone from key 2 on the keyboard, I need this key for something else, but the damn binoculars are locked to this key. Does anybody know how to rebind them to key 0?

Sadly, I think they only allow you to bind the number keys 1, and 3 to 8, unless you use some kind of mod.

I think the keybinding for the "2" key is hard coded and can't be changed. That key is used for switching between various ammo types (armor piercing, hollow point, standard, etc.) for your currently equipped weapon.