The Rebel has summed up the reason why this debate is going nowhere, brilliantly - equating gun ownership to democracy - only the US's radical brand of Lockean liberalism results in this type of thinking - it is the ideological element that takes it beyond rational debate. Simon - if I were you I would stop wasting your time trying to reason with the pro-gun writers. Their ideology prevents them from engaging in a rational discourse.
I read an interesting article in the LA Times on why the US is a global superpower in mass shootings. It put forward four factors that when taken together sets the US apart: 1. gun ownership - at 88.8 guns per 100 people the US has by far the highest (Yemen is second with around 50 per 100); 2. the way the American dream creates frustration and a sense of failure by creating personal expectations that many are incapable of achieving; 3. the cult of celebrity at any price; and 4. the poor quality of mental healthcare.