[pjc50]

You're thinking like an American: bigger is better :)

UK armed robberies are often [citation needed] carried out with imitation or deactivated firearms, as the robbers neither need nor want to kill anyone and it's considerably cheaper, easier to get hold of, and less illegal.

http://webarchive.nationalarchives.gov.uk/20160105160709/htt... page 6 has a breakdown graph into shotguns, handguns, imitation (includes air and BB), and "other".