As far as I can tell, this "buckshot theory of photons" is a heuristic that is never actually formalized or used in serious calculations. In actual quantum optics calculations I have seen, a photon is a quantized excitation of a mode of an optical system, and it is definitely not localized to a moving point in space. There are "wave packets" that are somewhat localized in space and move together, but these are not the same as "photons".