I want to hate guns' prevalence in the US and do, but it seems that enough places have initiated gun bans without a clear benefit that it's really hard to argue that taking a culture and making legal ownership much harder has an immediate benefit or even one within a few years. Who knows what would happen several decades down the road, but it's a bit like pandora's box in that when opened you cannot close it.
The UK may very well have lower murder rates than the US. I bet it does. I bet also that it has higher rates of mugging and home invasions. Crime rates are influenced by culture as well. The home invasion rate in the US is really not bad at all. I don't know if it's because of guns or not, but when looking at a picture of crime in a country one needs to consider rape, assault, home invasions, murder, etc. From what I have seen, the US is substantially a safer place to live than the UK. Guns don't really help or hurt this because in reality the average joe will never come upon a drawn gun in either country and the comparitively high murder rates in the US are still "fairly low" not to mention a great deal are the result of drug wars or among people who those of us on anandtech will never meet (e.g., we don't hang around trash, most likely).