"The "rifles" are bayonet-practice dummies made from old Martinis -- which is why the two men are goofing around. In place of the barrel there is a tube containing a plunger on a spring, which telescopes down when you thrust again someone or something (as with the Gurkha in the foreground, thrusting against the ground. This will soon be the only sort of "firearm" permitted in UK!"
Well, that explains the photo. I did have a hard time believing that folks who really knew firearms would behave thus, but I let the cynical side of myself get the better of me. Unfortunately it seems to be common occurence that is more often correct than not, albeit not in this case. Maybe there is some hope after all.
I did notice the blunt-ended projections in the less than wonderful photos, but my unfamiarity with arms of this era led me to assume that it was an included cleaning rod or the like.