Can anyone help me complete the campaign with only melee weapons?

[thepillow]

It's so difficult to put together a lobby in l4d these days.
I came up with this idea to get the corresponding achievement, but I don’t know if you can use pistols when you’re down, or if you can use grenades.

[jjoongrami]

it's doable as single player, even in normal mode. i do suggest you do it on easy in dead center (you're automatically unarmed of primary weapon). you can't use pistols if you're down, but you can use throwables-- in fact, i suggest you ALWAYS have one. also, don't use the chainsaw in this as when you run out of ammo, you'll auto resort to pistols. best of luck!

[thepillow]

Thank you very much for all the information.