The much-faster Peter, complete with Peter Tingle (goodness, Marvel/Sony, how hard did we have to force that one down?), will just web him before Scott can react. Even if he manages to shrink, Pete proved just fine that he can dodge dozens of automatic weapons that he can't see, hear or smell and deliver a hit on his foe who he also can't see hear or smell, thanks to his Peter Tingle.
Like in so many situations, speed kills.