Good point Gecko, although you have to factor in whether someone who might want to buy a gun on a whim would do so if they were not so easy to buy.
I was thinking more of 'spur of the moment gun crimes' resulting in multiple killings, like Columbine or crimes of passion etc rather than criminals to whom the gun is a tool of their trade.
I do have a sad feeling that Lasz might be right about the proliferation of unlicensed weapons being used for crime in the UK reaching such a high volume that at some point law abiding citizens will pass laws for 'concealed carry' here. We are still some way from that point (and I hope we never get there), although I think the US has passed that point by the sheer number of guns floating around in the country.
Although we still have a relatively small incidence of illegal gun ownership compared to you lot, the number appears to be rising (just IMHO - I have not seen any numbers on this).
For the first time in our history, a couple of weeks ago (I'm surprised it hasn't been mentioned by the pro gun lobby here) someone with a gun held up diners in a swanky restaurant in London and relieved them of their valuables. My fear is that with the press coverage it received copy cat crimes will follow.
I still don't think we need concealed carry in the UK, but that is something which should always be under review.
Ravs