I'm not disputing the facts Ed - just pointing out that it is unusual here to find people who have even seen a real gun, close to, let alone touched one. Totally different to the maths of the USA. Half a million of the guns you mention are shotguns, and of course many legitimate owners have more than one. If you look at the nearly 70 million population, and the non-shotgun owners - they're a tiny proportion, and they own them for work, for sport or other sensible reasons. Ordinary people do not have a firearm, just in case? Just in case of what? A little old lady, unhappy with criminals in her area cannot own a gun, just in case she gets burgled and wants to shoot them?
Even noise or flash suppressors need a licence here, and 32% of the licences are for those, included in the figures - so we have a tiny percentage of the population who have a firearms licence - but that won't stop criminals I suppose.