Howling:Firearm Continuity?

I was re-watching Waters of Mars yesterday, and I noticed something. Adelaide had a sort of energy/phaser sort of weapon, that you would assume they would have in the future. The thing is though, weapons seem to devolve over the course of history. In Bad Wolf and The Parting of the Ways, which occurs after the events of WoM, they are using rifles with bullets again. The same goes for the battle between the Humans and the Hath in The Doctor's Daughter, where they are once again using rifles with bullets. General Cobb even uses a revolver to shoot Jenny. Any thoughts?