McClane.
However. Given his armor and reaction time Batman should be able to escape the original encounter. Not because he can dodge bullets. Rather because he has a shot at dodging McClanes shots/aim. Remember they see each other at the same time and John is understandable baffled by Bat's appearance, but lets assume Mac immidiatly assumes Bat's is a wacked out terrorist. John's first thought is shoot, Bats first thought is move. Now given on screen feats i'd say Bruce has better reaction time(though McClane is by no means slow). That aside though if Bats is hitting the deck at the same time Mac is shooting then Mac is at the very least not going to hit him were he wants to. Which with Wayne's armor coverage gives him a good chance at surviving and rolling out of the way of the next shot. Infact even if Bat's took the first couple of shots before he got the dodge off. Mac being a cop is likely going to be shooting for center mass. Meaning Bruce has a good shot at surviving anyway.
Now that we are past the initial encounter. At some point Batman is going to close the distance and get up close and personel. That's how he opperates. He is most comfortable at melee range. Unfortunatly. This is where things go down hill for him. Considering the guys that Mac has taken out in CQC and the beating he can take. Batman pounds on him for a spell until Johny boy gets his opening and knocks Batman the fu<k out.
Yeah I said it. McClane doesn't win because he shoots Batman. He win because he straight up beats his head in. Well Bale Batman anyway. Anthology Batman would cave his skull in.