cg_gunx, cg_guny and cg_gunz would do that but these cvars are cheat protected. I'm not sure as I don't see what advantage can come from abusing these cvars but anyway....
I've been playing with drawgun set to 0 for a long time but I still fuck up on a regular basis because what I expect in the heat of the moment is not always what it actually is (LET ME KILL YOU WITH T ...