I am now about 25% through The Long War, sequel to The Long Earth by Terry Pratchett and just noticed that they are talking about "armed soldiers", "pistol-whipping", and other things. However, in The Long Earth, one of the bigger constraints on the expansion of Datum Earth's governments' influence was the fact that you could not transport ferrous metals when stepping. In fact, the Twain technology used airships constructed from nonmetallic components.
Was this restriction retconned out of existence?