Sure bullets make noise but a piece of kryptonite encased in a normal lead bullet doesn't make a strange noise or act in anyway like an abnormal bullet. How many time has superman let bullets bounce off of him? He seems to take great pleasure in it for some odd reason. As an aside could you even be charged for shooting superman with a normal bullet?
I was never suggesting a Superman vs. Wolverine fight but but if I had to choose a Nemesis I would choose Superman. Sure if he ever got me alone without Kryptonite he could kill me easily, but he wouldn't. He would probably give me a patronizing look and a stern talking too while either waiting for the police to show up or flying me to them. Wolverine...not so much.