It also seems to be focusing on arms that represented a particular innovation. For example, there's a good deal of time spent on the original 1895 machine gun, but the one that really made a statement, Ma Deuce, is simply mentioned as a different caliber. From the point of view of technological innovation, that's really all it is. The same thing goes for the semiauto pistols. The 1911 is a larger caliber refinement of the Colt and FN semiautos that had been on the market since the turn of the century.
Ken