Ok, changing keybindings in the options menu allows you to move the "switch ammo" action to a different key of your chosing, but - atleast for me - it still doesn't allow me to bind any weapon/consumable to the 2-key. Instead i now have "switch ammo" on both the 2-key and whichever key i chose for this action.
Has anyone been successfull at binding an item to the 2-key?

I'm pretty sure the "switch ammo" function HAS to be mapped. I don't think there is an option around it.

Yeah i know. And i tried to map it to another key (h-key to be specific) and then bind something else to 2 afterwards, yet without success

Been going through every readable file in the game directory aswell since i figure there's bound to be some value we can change to "unlock" the 2 key. Haven't found such a thing yet.

This is a little bit annoying for me to have one of the hotkeys preset - I've played Oblivion and FO3 repeatedly for more than 1000 hours between both games, they have the same hotkey system, and in those games I ALWAYS have my favourite weapons bound to hotkeys 1 and 2 (usually 1 ranged and 1 melee). Now that I have New Vegas I find I am out of habit pressing button 2 and switching ammo by mistake in mid-combat instead of switching weapons.

Surely there must be some way of making it customisable, I'd rather have it on the "t" key because it's next to the draw/reload "r" button and have hotkey 2 free to assign to my secondary weapon. Hey, I'm not as young as I used to be, and it takes longer to get used to these things - it would be easier if I could set it up the way I am used to playing Oblivion and FO3! Great game however, this is just a little annoyance.