Its faster to switch to your rocks than to reload your gun

It also helps make the fact that he's definitely the strawhat who cares most about the crew ( after Luffy and tied with Sanji of course) more believable.

I know that Zoro doesn't shower enough for someone who sweats and bleeds as much as him but you know what i find absolutely crazy, oda has said in an sbs that he would smell of steel. How does that even happen ?

And yet Oda said that zoro would smell of steel